Claims
- 1. A method of making a silver base electrical contact material, said method comprising the steps of:
- preparing a silver-nickel liquid solution containing 1 to 5 wt % of nickel;
- applying a high pressure water jet in collision with a stream of said sliver-nickel liquid solution in order to atomize said liquid solution into a resulting silver-nickel alloy powder which is inoculated with oxygen supplied from within said high pressure water, said alloy powder containing nickel particles having an average particle size of not more than 1 .mu.m and being uniformly dispersed in a silver matrix;
- blending said alloy powder with an additional nickel powder to form a compact;
- sintering said compact in such a manner as to internally oxidize nickel with said embedded oxygen to obtain a resulting sintered material containing nickel and nickel oxide particles dispersed in said sliver matrix,
- wherein the resultant material contains 0.5 to 39.9 wt % of nickel, 0.14 to 7.0 wt % of nickel oxides, and balance silver, and contains not less than 0.4 wt % of nickel constituting said nickel and nickel particles having a particle size of not more than 1 .mu.m.
- 2. A method as set forth in claim 1, wherein said silver-nickel alloy powder has an average particle size of not more than 45 .mu.m.
- 3. A method as set forth in claim 1, wherein said additional nickel powder is a carbonyl nickel powder having an average particle size of 10 .mu.m.
- 4. A method as set forth in claim 1, wherein said nickel and nickel oxide particles have a particle size of not more than 10 .mu.m.
- 5. A method as set forth in claim 1, wherein said sintered material is drawn in one direction to make a contact surface with a reduced cross-section perpendicular to the drawing direction.
- 6. A method of making a silver base electrical contact material, said method comprising the steps of:
- preparing a silver-nickel liquid solution containing 1 to 5 wt % of nickel;
- applying a high pressure water jet in collision with a stream of said sliver-nickel liquid solution in order to atomize said liquid solution into a resulting silver-nickel alloy powder which is inoculated with oxygen supplied from within said high pressure water, said alloy powder containing nickel particles having an average particle size of not more than 1 .mu.m and being dispersed in a silver matrix;
- blending said alloy powder with an additional nickel powder to form a compact;
- sintering said compact in such a manner as to internally oxidize nickel with said embedded oxygen to obtain a resulting sintered material containing nickel and nickel oxide particles dispersed in a silver matrix.
- 7. A method of making a silver base electrical contact material, said method comprising the steps of:
- preparing a silver-nickel liquid solution containing 1 to 5% wt % of nickel;
- atomizing said liquid solution to obtain a silver-nickel alloy powder containing nickel particles which are dispersed in a silver matrix and have an average particle size of not more than 1 .mu.m;
- processing said alloy powder at a temperature of about 450.degree. C. to internally oxidize nickel such that said alloy powder includes nickel oxide particles;
- blending said oxidized alloy powder with an additional nickel powder to form a compact thereof; and
- sintering said compact to obtain said contact material in which nickel and nickel oxide particles are dispersed in a matrix of said silver,
- wherein the resultant material contains 0.5 to 39.9 wt % of nickel, 0.14 to 7.0 wt % of nickel oxides, and balance silver, and said material contains not less than 0.4 wt % of nickel constituting said nickel and nickel particles having a particle size of not more than 1 .mu.m.
- 8. A method as set forth in claim 7, wherein said silver-nickel alloy powder has an average particle size of not more than 45 .mu.m.
- 9. A method as set forth in claim 7, wherein said additional nickel powder is a carbonyl nickel powder having an average particle size of 10 .mu.m.
- 10. A method as set forth in claim 7, wherein said sintered material is drawn in one direction to make a contact surface with a reduced cross-section perpendicular to the drawing direction.
Priority Claims (2)
Number |
Date |
Country |
Kind |
2-164839 |
Jun 1990 |
JPX |
|
3-139826 |
May 1991 |
JPX |
|
Parent Case Info
This is a division of application Ser. No. 07/718,035 filed Jun. 20, 1991, now U.S. Pat. No. 5,198,015.
US Referenced Citations (7)
Non-Patent Literature Citations (2)
Entry |
Goetzel, Claus G., "Treatise on Powder Metallurgy", vol. 1, pp. 656-661, 666-672, 1949. |
Dixon, et al. "Powder Metallurgy for Engineers", pp. 30-45, 1971. |
Divisions (1)
|
Number |
Date |
Country |
Parent |
718035 |
Jun 1991 |
|