The disclosure relates to a method for manufacturing a three-dimensional shaped object. More particularly, the disclosure relates to a method for manufacturing a three-dimensional shaped object, in which a formation of a solidified layer is performed by an irradiation of a powder layer with a light beam.
Heretofore, a method for manufacturing a three-dimensional shaped object by irradiating a powder material with a light beam has been known (such method can be generally referred to as “selective laser sintering method”). The method can produce the three-dimensional shaped object by an alternate repetition of a powder-layer forming and a solidified-layer forming on the basis of the following (i) and (ii):
(i) forming a solidified layer by irradiating a predetermined portion of a powder layer with a light beam, thereby allowing a sintering of the predetermined portion of the powder or a melting and subsequent solidification of the predetermined portion; and
(ii) forming another solidified layer by forming a new powder layer on the formed solidified layer, followed by similarly irradiating the powder layer with the light beam.
This kind of the manufacturing technology makes it possible to produce the three-dimensional shaped object with its complicated contour shape in a short period of time. The three-dimensional shaped object can be used as a metal mold in a case where inorganic powder material (e.g., metal powder material) is used as the powder material. While on the other hand, the three-dimensional shaped object can also be used as various kinds of models or replicas in a case where organic powder material (e.g., resin powder material) is used as the powder material.
Taking a case as an example wherein the metal powder is used as the powder material, and the three-dimensional shaped object produced therefrom is used as the metal mold, the selective laser sintering method will now be briefly described. A powder is firstly transferred onto abase plate 21 by a movement of a squeegee blade 23, and thereby a powder layer 22 with its predetermined thickness is formed on the base plate 21 (see
PATENT DOCUMENT 1: Japanese Unexamined Patent Application Publication No. 2002-115004
PATENT DOCUMENT 2: Japanese Unexamined Patent Application Publication No. 2000-73108
There is a case when a surface of the three-dimensional shaped object is subjected to a machining process. Specifically, in order to form the three-dimensional shaped object with a better shape accuracy, a surface of the solidified layer of the three-dimensional shaped object may be subjected to the machining process. A rotary machining tool such as a ball end mill is generally used at a point in time when the surface machining process is performed.
For example, when the ball end mill is used to perform the surface machining process, a machining resistance of the ball end mill cannot be ignored, and also the ball end mill may contact a waste caused by the machining, which may make a life time of the ball end mill shoter.
Under these circumstances, the present invention has been created. That is, an object of the present invention is to provide a manufacturing method of the three-dimensional shaped object, the method being capable of making a life time of a machining tool longer when the machining of the surface of the solidified layer is performed by using the machining tool.
In order to achieve the above object, an embodiment of the present invention provides a method for manufacturing a three-dimensional shaped object by alternate repetition of a powder-layer forming and a solidified-layer forming, the repetition comprising:
(i) forming a solidified layer by irradiating a predetermined portion of a powder layer with a light beam, thereby allowing a sintering of the powder in the predetermined portion or a melting and subsequent solidification of the powder; and
(ii) forming another solidified layer by forming a new powder layer on the formed solidified layer, followed by irradiation of a predetermined portion of the newly formed powder layer with the light beam,
wherein a surface of the solidified layer is subjected to a machining process, the machining process being performed on a basis of a condition of an ultrasonic vibration.
According to an embodiment of the present invention, it is possible to make the life time of the machining tool longer when the machining of the surface of the solidified layer is performed by using the machining tool.
The present invention will be described in more detail with reference to the accompanying drawings. It should be noted that configurations/forms and dimensional proportions in the drawings are merely for illustrative purposes, and thus not the same as those of the actual parts or elements.
The term “powder layer” as used in this description means a “metal powder layer made of a metal powder” or “resin powder layer made of a resin powder”, for example. The term “predetermined portion of a powder layer” as used herein substantially means a portion of a three-dimensional shaped object to be manufactured. As such, a powder present in such predetermined portion is irradiated with a light beam, and thereby the powder undergoes a sintering or a melting and subsequent solidification to form a shape of a three-dimensional shaped object. Furthermore, the term “solidified layer” substantially means a “sintered layer” in a case where the powder layer is a metal powder layer, whereas term “solidified layer” substantially means a “cured layer” in a case where the powder layer is a resin powder layer.
The directions of “upper” and “lower”, which are directly or indirectly used herein, are ones based on a positional relationship between a base plate and a three-dimensional shaped object. The side in which the manufactured three-dimensional shaped object is positined with respect to the based plate is “upper”, and the opposite direction thereto is “lower”. The “vertical direction” described herein substantially means a direction in which the solidified layers are stacked, and corresponds to “upper and lower direction” in drawings. The “horizontal direction” described herein substantially means a direction vertical to the direction in which the solidified layers are stacked, and corresponds to “right to left direction” in drawings.
First of all, a selective laser sintering method, on which an embodiment of the manufacturing method of the present invention is based, will be described. By way of example, a laser-sintering/machining hybrid process wherein a machining is additionally carried out in the selective laser sintering method will be especially explained.
As shown in
The powder layer former 2 is a means for forming a powder layer with its predetermined thickness through a supply of powder (e.g., a metal powder or a resin powder). The light-beam irradiator 3 is a means for irradiating a predetermined portion of the powder layer with a light beam “L”. The machining means 4 is a means for milling the side surface of the stacked solidified layers, i.e., the surface of the three-dimensional shaped object.
As shown in
As shown in
As shown in
Operations of the laser sintering hybrid milling machine 1 will now be described in detail. As can be seen from the flowchart of
The powder layer forming step (S1) and the solidified layer forming step (S2) are alternately repeated.
This allows a plurality of the solidified layers 24 to be integrally stacked with each other, as shown in
When the thickness of the stacked solidified layers 24 reaches a predetermined value (S24), the machining step (S3) is initiated. The machining step (S3) is a step for milling the side surface of the stacked solidified layers 24, i.e., the surface of the three-dimensional shaped object. The end mill 40 is actuated in order to initiate an execution of the machining step (S31). For example, in a case where the end mill 40 has an effective milling length of 3 mm, a machining can be performed with a milling depth of 3 mm. Therefore, supposing that “Δt” is 0.05 mm, the end mill 40 is actuated when the formation of the sixty solidified layers 24 is completed. Specifically, the side face of the stacked solidified layers 24 is subjected to the surface machining (S32) through a movement of the end mill 40 driven by the actuator 41. Subsequent to the surface machining step (S3), it is judged whether or not the whole three-dimensional shaped object has been obtained (S33). When the desired three-dimensional shaped object has not yet been obtained, the step returns to the powder layer forming step (S1). Thereafter, the steps S1 through S3 are repeatedly performed again wherein the further stacking of the solidified layers 24 and the further machining process therefor are similarly performed, which eventually leads to a provision of the desired three-dimensional shaped object.
An embodiment of the present invention is characterized by the machining step for the surface of the solidified layer in the selective laser sintering method.
A technical common knowledge of the skilled person (i.e., the skilled person in the technical field of the three-dimensional shaped object) regarding the machining process for the surface of the solidified layer before describing a feature of the present invention.
Upon the machining process of the surface of the solidified layer, a side surface of the solidified layer is subjected to the machining process by using a rotary machining tool such as the end mill. In this regard, it is a general for the skilled person that the machining process by using the rotary machining tool is performed with no vibration. This is because a provision of the vibration during the machining process for the side surface of the solidified layer is not effective, which is attributed to such a technical common knowledge of the skilled person that a vertical directional vibration of the machining tool is relatively easier than a horizontal directional vibration thereof upon the vibration of the machining tool, since a machining device having the rotary machining tool mainly has a function for rotating the rotary machining tool.
In
The present invention is characterized in that the machining process of the surface of the solidified layer is performed on the basis of the condition of the ultrasonic vibration, the machining process on the condition of the ultrasonic vibration being consciously/intentionally contrary to the above skilled person's technical common knowledge.
A manufacturing method according to an embodiment of the present invention will be specifically described hereinafter.
A technical concept of the present invention will be described with reference to
The technical concept of the present invention is that “the machining process of the surface of the solidified layer 24 is performed on the basis of the condition of the ultrasonic vibration”. Briefly, as shown in
In the present invention, the portion to be machined in the surface of the solidified layer 24 is provided with the ultrasonic vibration upon the machining of the surface of the solidified layer, which allows alternate “contact” and “non-contact” between the machining tool 40 and the portion to be machined in the surface of the solidified layer 24. In other words, the ultrasonic vibration contributes to an increase of an “intermittent” contact between the machining tool 40 and the portion to be machined. Thus, the increase of the intermittent contact allows an increase of the number of the contact between the machining tool 4C and the portion to be machined, which can make a size of a waste arising from the portion to be machined smaller, the waste being caused by the machining. The smaller size of the waste allows a prevention of a contact of the machining tool 40 with the waste. Furthermore, the present invention allows the increase of “intermittent” contact between the machining tool 40 and the portion to be machined. In other words, the present invention allows a prevention of a “continuous” or “constant” contact between the machining tool 40 and the portion to be machined in the surface of the solidified layer 24 upon the machining. The prevention of the “continuous” or “constant” allows a reduction of the machining resistance of the machining tool 40 to the portion to be machined in the surface of the solidified layer 24, and allows a prevention of a heat caused by the machining. Accordingly, it is possible to prevent a damage of the machining tool 40 and thereby to make a life time of the machining tool 40 longer.
The mark in the shape of circle arises in the machined portion of the solidified layer upon the machining of the surface of the solidified layer by using the machining tool (e.g. the rotary machining tool), the mark being attributed to the machining. As a result, the machined portion may have the large surface roughness. In this regard, the present invention allows the prevention of the “continuous” or “constant” contact between the machining tool 40 and the portion to be machined in the surface of the solidified layer 24 upon the machining, as described above. Therefore, the arising of the mark attributed to the machining can be prevented, which can make the surface roughness of the machined portion smaller.
The alternate “contact” and “non-contact” between the machining tool and the portion to be machined in the surface of the solidified layer may be performed in a normal vibration-condition (i.e., a non-ultrasonic vibration-condition). In this regard, a frequency of the normal vibration-condition is lower than that of the ultrasonic vibration. Thus, the number of the contact between the machining tool and the portion to be machined in the surface of the solidified layer becomes smaller, and a contact time therebetween becomes longer. As a result, it is difficult to obtain the above technical effects on “the provision of the machining tool having the longer lifetime” and “the provision of the machined portion having the smaller surface roughness”.
Hereinafter, specific embodiments of the present invention will be described.
The specific embodiments of the present invention are composed of two embodiments. A first embodiment of the present invention is based on such a technical idea that the machining tool is subjected to the ultrasonic vibration. second embodiment of the present invention is based on such a technical idea that the base plate is subjected to the ultrasonic vibration.
The first embodiment of the present invention will be described hereinafter, the first embodiment of the present invention having the technical idea that “the machining tool is subjected to the ultrasonic vibration”.
In the first embodiment of the present invention, the machininging for the surface of the solidified layer 24 is performed by using the machining tool 40 with the ultrasonic vibration as shown in
Hereinafter, such an embodiment wherein the machining for the surface of the solidified layer is performed by using the “rotary machining tool” with the ultrasonic vibration will be described. The embodiment is composed of three cases. The three cases will be specifically described, respectively.
Firstly, a case 1 will be described.
The powder layer is irradiated with the light beam L to form the solidified layer 24 as shown in
Subsequently, as shown in
As a first technical feature of this embodiment according to the present invention, the vibration direction of the rotary machining tool in the “rough process” is set to the vertical direction (i.e., upper and lower direction). On the other hand, the vibration direction of the rotary machining tool in the “machining-finishing process” is set to the horizontal direction (i.e., right to left direction). This means that the vibration direction of the rotary machining tool 43 is changed from the “vertical direction” to the “horizontal direction” during the machining process. The change of the vibration direction can result from a change of a vibration direction of the vibration mechanism 42 from the “upper and lower direction” to the “right to left direction” as shown in
The rough process allows contact portions between the rotary machining tool 43 and the surface of the solidified layer 24 to become different from each other along the upper and lower direction, the contact portions being formed upon the machining process, which can make the surface roughness of the machined portion in the solidified layer smaller. Specifically, the “rough process” allows a forming of a machined portion having Rz (i.e., an arithmetic mean roughness) of 5 (excluding 5)-10 (excluding 10) μm, preferably 5.5-9.5 μm, more preferably 6.0-9.0 μm, or even more preferably 6.5-8.5 μm, the machined portion corresponding to a portion subjected to the rough process. Subsequently, the machining-finishing process allows a provision of the vibration having the amplitude smaller than that in the rough process, which can provide a more alternate “contact” and “non-contact” between the rotary machining tool 43 and the portion to be machined in the surface of the solidified layer 24. Thus, the more alternate “contact” and “non-contact” can make the surface roughness of the machined portion smaller. Specifically, the “machining-finishing process” allows a forming of the machined portion having Rz of 2.5-8.5 μm, preferably 3.5-7.5 μm, more preferably 4.5-6.5 μm, or even more preferably 5.0-6.0 μm, the machined portion corresponding to a portion subjected to the machining-finishing process. The term “arithmetic mean roughness Rz” is roughness “Rz” defined in JIS B0601. More specifically, the term “arithmetic mean roughness Rz” as used herein means the sum value (μm) of the average of absolute values from the uppermost mountain peak (Yp) to the fifth mountain peak (Yp) and the average of absolute values from the lowermost valley portion (Yv) to the fifth valley portion (Yv), the mountain peak and the valley portion being measured perpendicularly from the average line over the length of an evaluation section that is set in the roughness curve. See JIS B0601:1994.
Secondly, a case 2 will be described.
The powder layer is irradiated with the light beam L to form the solidified layer 24 as shown in
An embodiment according to the present invention has a first feature that the solidified layer is subjected to the “rough process” by using the rotary machining tool 43 having its vertical vibration direction, followed by the “polishing-finishing process” by using the grinding tool 44 with the shaft. An embodiment according to the present invention has a second feature that an amplitude of the vertical directional vibration of the rotary machining tool 43 is larger than that of the horizontal directional vibration of the grinding tool 44 with the shaft. The rough process allows contact portions between the rotary machining tool 43 and the surface of the solidified layer 24 to become different from each other along the upper and lower direction, the contact portions being formed upon the machining process, which can make the surface roughness of the machined portion in the solidified layer smaller. Specifically, the “rough process” allows a forming of the machined portion having Rz of 5 (excluding 5)-10 (excluding 10) μm, preferably 5.5-9.5 μm, more preferably 6.0-9.0 μm, or even more preferably 6.5-8.5 the machined portion corresponding to a portion subjected to the rough process. In the subsequent “polishing-finishing process”, the rough processed portion in the surface of the solidified layer 24 is subjected to the polishing by using the grinding tool 44 with the shaft, which can make the surface roughness of the machined portion in the solidified layer much smaller. Specifically, the “polishing-finishing process” allows a forming of the portion subjected to the polishing-finishing process having Rz of 1-7 μm, preferably 2-6 μm, more preferably 3-5 μm, or even more preferably 3.5-4.5 μm.
Finally, a case 3 will be described.
The powder layer is irradiated with the light beam L to form the solidified layer 24 as shown in
Firstly, the rough process allows contact portions between the rotary machining tool 43 and the surface of the solidified layer 24 to become different from each other along the upper and lower direction, which can make the surface roughness of the machined portion in the solidified layer smaller. Specifically, the “rough process” allows a forming of the machined portion having Rz of 5 (excluding 5)-10 (excluding 10) μm, preferably 5.5-9.5 μm, more preferably 6.0-9.0 μm, or even more preferably 6.5-8.5 μm, the machined portion corresponding to a portion subjected to the rough process. The subsequent machining-finishing process allows a provision of the vibration having the amplitude smaller than that in the rough process, which can provide a more alternate “contact” and “non-contact” between the rotary machining tool 43 and the portion to be machined in the surface of the solidified layer 24. Thus, the more alternate “contact” and “non-contact” can make the surface roughness of the machined portion much smaller. Specifically, the “machining-finishing process” subsequent to the “rough process” allows a forming of a machining-finishing processed portion having Rz of 2.5-8.5 μm, preferably 3.5-7.5 μm, more preferably 4.5-6.5 μm, or even more preferably 5.0-6.0 μm. Furthermore, in subsequent “polishing-finishing process”, the machining-finishing processed portion in the surface of the solidified layer 24 is subjected-to the polishing by using the grinding tool 44 with the shaft, which can make a surface roughness of the machining-finishing processed portion even much smaller. Specifically, the “polishing-finishing process” subsequent to the “machining-finishing process” allows a forming of the portion subjected to the polishing-finishing process having Rz of 1-7 μm, preferably 2-6 μm, more preferably 3-5 μm, or even more preferably 3.5-4.5 μm.
In light of the above matters, the case 3 is effective in that it allows a provision of the smaller surface roughness of the machined portion compared to the patterns 1 and 2.
In the case 3, each surface of a plurality of the solidified layers may be sequentially subjected to the rough process, the machining-finishing process by using the rotary machining tool 43 with the ultrasonic vibration, and polishing-finishing process (see
Three cases have been described, the cases including an embodiment wherein the machining process for the surface of the solidified layer is performed by using the “rotary machining tool” with the ultrasonic vibration.
An embodiment wherein a “non-rotary machining tool”, not “rotary machining tool” is used as the machining tool for performing the machining process will be described hereinafter.
In an embodiment according to the present invention, a non-rotary machining tool is used as the machining tool for the machining process. In the non-rotary machining tool, a portion for performing the machining process has no function of a rotation motion. The “non-rotary machining tool” means a tool having no function of the rotation motion upon the machining process. The non-rotary machining tool may include a spring necked turning tool which is made of a diamond and/or superhard material for example.
An embodiment according to the present invention has a feature that the non-rotary machining tool having no function of the rotation motion is subjected to the ultrasonic vibration during the machining process. Even when the non-rotary machining tool is used, its ultrasonic vibration is possible and thus it is possible to perform the alternate “contact” and “non-contact” between the machining tool for the machining process (i.e., non-rotary machining tool) and the portion to be machined in the surface of the solidified layer, which can make the lifetime of the non-rotary machining tool longer.
It is preferable that the non-rotary machining tool is subjected to the ultrasonic vibration as described above. Specifically, it is preferable that, by using the non-rotary machining tool with the ultrasonic vibration, a portion to be machined in the surface of the solidified layer is provided with an ultrasonic elliptical vibration.
More specifically, a chip portion 46 disposed on a tip portion of the non-rotary machining tool 45 provides a portion to be machined in the surface of the solidified layer 24 with the ultrasonic elliptical vibration as shown in
The first embodiment of the present invention has been described, the first embodiment being based on such a technical idea that “the machining tool is subjected to the ultrasonic vibration”.
The second embodiment of the present invention will be described hereinafter, the second embodiment being based on such a technical idea that “the base plate is subjected to the ultrasonic vibration”.
In the second embodiment of the present invention, a forming table 20 with an ultrasonic vibration is used to perform the machining process of the surface of the solidified layer 24, the forming table 20 being provided for forming the powder layer and the solidified layer at an upper region thereof. Specifically, a based plate 21 disposed on the forming table 20 with the ultrasonic vibration is used for the machining process. This means that the second embodiment of the present invention has such a feature that the machining for the surface of the solidified layer 24 is performed in a state that a portion to be machined in the surface of the solidified layer 24 is provided with an ultrasonic vibration which is due to the forming table 20 subjected to the ultrasonic vibration. While not being limited to a specific embodiment, a vibrator which is capable of an ultrasonic vibration in a vertical direction or a horizontal direction may result in the forming table 20 with the ultrasonic vibration in a vertical direction or a horizontal direction, the vibrator being disposed in the base plate 21 or the forming table 20. A use of the forming table 20 on the condition of the ultrasonic vibration in the vertical direction allows contact portions between the machining tool 40 and the surface of the solidified layer 24 to become different from each other along the upper and lower direction, the contact portions being formed upon the machining process, which can make the surface roughness of the machined portion in the solidified layer smaller. A use of the forming table 20 on the condition of the ultrasonic vibration in the horizontal direction allows alternate “contact” and “non-contact” between the machining tool 40 and the portion to be machined in the surface of the solidified layer 24, which can make the surface roughness of the machined portion in the solidified layer smaller. It is preferable that the forming table 20 is provided with the vertical directional ultrasonic vibration in light of a position-relationship between the forming table 20 and the wall 27, the position-relationship being that a side surface of the forming table 20 contacts the wall 27.
Although several embodiments of the present invention (i.e., the method for manufacturing the three-dimensional shaped object) have been hereinbefore described, the present invention is not limited to these embodiments. It will be readily appreciated by the skilled person that various modifications are possible without departing from the scope of the present invention.
Examples related to the present invention will be described hereinafter.
The machining process of the solidified layer having a groove portion a concave portion) was performed by using the machining tool. Specifically, as shown in
The machining process of the surface of the solidified layer having the groove portion was performed by using the end mill with the ultrasonic vibration, the end mill having AlTiN coating and R: 0.3 mm. Subsequently, the polishing process for a machined surface was performed by using the grinding tool with the shaft subjected to the ultrasonic vibration. Another enlarged photograph of the machined and subsequent polished portion on the condition of the ultrasonic vibration is shown in
Rotation number: 6000 min−1;
Vibration amplitude: 30-50 μm;
Frequency: 40 kHz; and
Vibration direction: Extension direction of end mill
The portion subjected to the machining process and subsequent polishing process each of which was on the condition of the ultrasonic vibration had little rough surface. On the other hand, the portion subjected to the machining process with no vibration had a remarkable rough surface.
The machining process for the surface of the solidified layer was performed by using the end mill with AlTiN coating (R: 0.3 mm) on a condition of a non-vibration. An abrasion state of a tip portion of the machining tool is shown in
The machining process for the surface of the solidified layer was performed by using the end mill with the ultrasonic vibration, the end mill having AlTiN coating and R: 0.3 mm. Another abrasion state of the tip portion of the machining tool is shown in
Rotation number: 6000 min−1;
Vibration amplitude: 30-50 μm;
Frequency: 40 kHz; and
Vibration direction: Extension direction of end mill
The tip portion of the end mill upon the completion of the machining process on the condition of the ultrasonic vibration had little abration surface even though the machined distance of the surface of the solidified layer was 100 m as of the completion of the machining process. On the other hand, the tip portion of the end mill upon the completion of the machining process with no vibration had a remarkable abration surface when the machined distance of the surface of the solidified layer was 100 m as of the completion of the machining process.
The machining process for the surface of the solidified layer was performed by using the end mill with AlTiN coating (R: 0.3 mm) on a condition of a non-vibration. A technical relationship between a machined distance of the surface of the solidified layer and an abrasion length of the tip portion of the machining tool was studied. A result of the technical relationship is shown in
The machining process for the surface of the solidified layer was performed by using the end mill with the ultrasonic vibration, the end mill having AlTiN coating and R: 0.3 mm.
Upon the use of the end mill on the condition of the ultrasonic vibration, another technical relationship between the machined distance of the surface of the solidified layer and the abrasion length of the tip portion of the machining tool is shown in
Rotation number: 6000 min−1;
Vibration amplitude: 30-50 μm;
Frequency: 40 kHz; and
Vibration direction: Extension direction of end mill
In a case where the machining process of the surface of the solidified layer was performed by using the endmill with the ultrasonic vibration, the abrasion length of the tip portion of the endmill was 20 μm or less even though the machined distance was about 800 m, and thus the tip portion had little abrasion state (see
The machining process for the surface of the solidified layer was performed by using the end mill with AlTiN coating (R: 0.3 mm) on a condition of a non-vibration. An enlarged photograph of a waste caused by the machining process with no vibration is shown in
The machining process for the surface of the solidified layer was performed by using the end mill with the ultrasonic vibration, the end mill having AlTiN coating and R: 0.3 mm. Another enlarged photograph of a waste caused by the machining process with the ultrasonic vibration is shown in
Rotation number: 6000 min−1;
Vibration amplitude: 30-50 μm;
Frequency: 40 kHz; and
Vibration direction: Extension direction of end mill
A size of the waste caused by the machining with the ultrasonic vibration was smaller than that of the waste caused by the machining with no vibration (see
The machining process for the surface of the solidified layer was performed by using the end mill with AlTiN coating (R: 0.3 mm) on a condition of a non-vibration. A technical relationship between a machined distance of the surface of the solidified layer and a machining resistance of the endmill with no vibration was studied. A result of the technical relationship is shown in
The machining process for the surface of the solidified layer was performed by using the end mill with the ultrasonic vibration, the end mill having AlTiN coating and R: 0.3 mm. Another technical relationship between the machined distance of the surface of the solidified layer and the machining resistance of the endmill with the ultrasonic vibration was studied. A result of another technical relationship is shown in
Rotation number: 6000 min−1;
Vibration amplitude: 30-50 μm;
Frequency: 40 kHz; and
Vibration direction: Extension direction of end mill
In a case where the machining process of the surface of the solidified layer was performed by using the endmill with the ultrasonic vibration, the machining resistance of the endmill with the ultrasonic vibration was about 4 N to about 12 N even though the machined distance was about 800 m (see
The machining process for the surface of the solidified layer was performed by using the end mill with AlTiN coating (R: 0.3 mm) on a condition of a non-vibration. A state of a burr occurrence upon the machining process with no vibration was studied. A result of the state of the burr occurrence is shown in
The machining process for the surface of the solidified layer was performed by using the end mill with the ultrasonic vibration, the end mill having AlTiN coating and R: 0.3 mm. Another state of a burr occurrence upon the machining process with the ultrasonic vibration was studied. A result of another state of the burr occurrence is shown in
Rotation number: 6000 min−1;
Vibration amplitude: 30-50 μm;
Frequency: 40 kHz; and
Vibration direction: Extension direction of end mill
In a case where the machining process of the surface of the solidified layer was performed on the condition of the ultrasonic vibration, a prevention of the burr occurrence can be found (see
The machining process for the surface of the solidified layer was performed by using the end mill with AlTiN coating (R: 0.3 mm) on a condition of a non-vibration. An enlarged photograph of a machined portion with no vibration is shown in
The machining process for the surface of the solidified layer was performed by using the end mill with the ultrasonic vibration, the end mill having AlTiN coating and R: 0.3 mm. Subsequently, a polishing process for the machined surface was performed by using a grinding tool with a shaft on the condition of the ultrasonic vibration. Another enlarged photograph of a portion subjected to the machining process and the polishing process with the ultrasonic vibration is shown in
Rotation number: 6000 min
Vibration amplitude: 30-50 μm;
Frequency: 40 kHz; and
Vibration direction: Extension direction of end mill
The portion subjected to the machining process and the polishing process with the ultrasonic vibration had a surface roughness (i.e., Rz) of 3-5 μm. On the other hand, the machined portion with no vibration had a surface roughness (i.e., Rz) of 10-30 μm.
It should be noted that the present invention as described above includes the following aspects:
The first aspect: A method for manufacturing a three-dimensional shaped object by alternate repetition of a powder-layer forming and a solidified-layer forming, the repetition comprising:
(i) forming a solidified layer by irradiating a predetermined portion of a powder layer with a light beam, thereby allowing a sintering of the powder in the predetermined portion or a melting and subsequent solidification of the powder; and
(ii) forming another solidified layer by forming a new powder layer on the formed solidified layer, followed by irradiation of a predetermined portion of the newly formed powder layer with the light beam,
wherein a surface of the solidified layer is subjected to a machining process, the machining process being performed on a basis of a condition of an ultrasonic vibration.
The second aspect: The method according to the first aspect, wherein a machining tool with an ultrasonic vibration is used for the condition of the ultrasonic vibration, the machining tool being used for the machining process.
The third aspect: The method according to the first or second aspect, wherein each of the powder layer and the solidified layer is formed at an upper region of a forming table, and wherein the forming table with an ultrasonic vibration is used for the condition of the ultrasonic vibration.
The fourth aspect: The method according to the second or third aspect, wherein a rotary machining tool is used as the machining tool, and
wherein the rotary machining tool with an ultrasonic vibration is provided while the the rotary machining tool being rotated.
The fifth aspect: The method according to the fourth aspect, wherein a change in a vibration direction of the rotary machining tool is performed between a vertical direction and a horizontal direction during the machining process.
The sixth aspect: The method according to the fifth aspect, wherein an amplitude of the vertical directional vibration of the rotary machining tool is larger than that of the horizontal directional vibration of the rotary machining tool.
The seventh aspect: The method according to any one of the first to sixth aspects, wherein the machining process is performed in at least two steps, the at least two steps comprising a rough process step and a finishing process step.
The eighth aspect: The method according to the seventh aspect, wherein any one of a machining-finishing, a polishing-finishing, and a combination of the machining-finishing and the polishing-finishing is performed as the finishing process, the machining-finishing using the rotary machining tool, the polishing-finishing using a grinding tool with a shaft.
The ninth aspect: The method according to the seventh aspect when appendant to the fifth or sixth aspect, wherein the rough process is performed by the rotary machining tool with the vertical directional vibration, and subsequently the finishing process is performed by the rotary machining tool with the horizontal directional vibration.
The tenth aspect: The method according to any one of the first to third aspects, wherein a non-rotary machining tool is used as the machining tool which is used for the machining process.
The eleventh aspect: The method according to the tenth aspect, wherein the non-rotary machining tool provides an ultrasonic elliptical vibration.
The manufacturing method according to an embodiment of the present invention can provide various kinds of articles. For example, in a case where the powder layer is a metal powder layer (i.e., inorganic powder layer) and thus the solidified layer corresponds to a sintered layer, the three-dimensional shaped object obtained by an embodiment of the present invention can be used as a metal mold for a plastic injection molding, a press molding, a die casting, a casting or a forging. While on the other hand in a case where the powder layer is a resin powder layer (i.e., organic powder layer) and thus the solidified layer corresponds to a cured layer, the three-dimensional shaped object obtained by an embodiment of the present invention can be used as a resin molded article.
The present application claims the right of priority of Japanese Patent Application No. 2015-127888 (filed on Jun. 25, 2015, the title of the invention: “METHOD FOR MANUFACTURING THREE-DIMENSIONAL SHAPED OBJECT”), the disclosure of which is incorporated herein by reference.
Number | Date | Country | Kind |
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2015-127888 | Jun 2015 | JP | national |
Filing Document | Filing Date | Country | Kind |
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PCT/JP2016/054352 | 2/9/2016 | WO | 00 |