Patent Application
20250084519
The present invention generally relates to the field of material science and metal alloy technology. More specifically, the present invention provides a strong-yet-ductile chemically complex alloy over a wide temperature range and its preparation method. The present invention paves the way for the development of CCAs exhibiting exceptional mechanical properties across a broad temperature spectrum through the implementation of chemical composition design and grain boundary engineering.
The pursuit of designing alloys with exceptionally high strength and ductility to enhance engineering reliability and energy efficiency under extreme environments (such as elevated temperatures) has consistently been a goal of researchers and industries. However, the design strategies for traditional alloys based on a single principal element may have reached a bottleneck in terms of optimizing properties.
The discovery of chemical complex alloys (CCAs) or high-entropy alloys (HEAs) based on multi-principal elements is considered as new paradigm for designing novel alloys with desirable properties1,2. Significantly, the multicomponent intermetallic L12 nanoparticle-reinforced CCAs have garnered substantial attention in recent years, creating fresh opportunities for the advancement of advanced structural materials possessing sought-after properties3. Currently, the majority of CCAs are formulated through the incorporation of Ti and Al elements, resulting in the creation of coherent Ni3(Al, Ti) particles for the purpose of hardening. Nevertheless, these types of CCAs experience drawbacks in terms of diminished strength and stability at elevated temperatures, stemming from inadequate volume fractions and low solvus temperatures of L12 particles. For example, Chen et al. found that the formation of L12 phase was preferred when the Ti/Al ratios ranged from 0.7-2 in CoCrFeNi-based HEAs4. However, high Al content leads to the formation of B2 phase, while high Ti content results in the decrease of solidus temperature and precipitation of the brittle D024 structured η-Ni3Ti phase5. Thus, the volume fraction of L12 phase is greatly restricted by the content of Al, and Ti. In addition, Qi et al. discovered that the refractory element Ta has a tendency to dissolve into the L12-Ni3(Al, Ti) phase, reducing the system's energy and resulting in an increased L12 volume fraction and solution temperature6. While these alloys demonstrate exceptional mechanical properties (e.g., tensile strength) at cryogenic and ambient temperatures, they encounter significant challenges in the form of intermediate temperature embrittlement (usually 0.5-0.7 Tm, Tm is the melting point) and reduced strength at elevated temperatures exceeding 1000° C. Intermediate temperature embrittlement (ITE) is a prevalent phenomenon observed in numerous structural materials, encompassing CCAs7, Ni-based8, Co-based9, and Fe-based superalloys10, as well as Cu and Al alloys11,12, among others. These crucial concerns considerably limit the potential applications of CCAs as high-temperature structural materials.
Numerous efforts have been undertaken to comprehend the mechanism behind ITE and to investigate viable strategies for addressing this significant issue. For instance, Zheng et al. ascribed the occurrence of ITE in Ni-based superalloys to nonequilibrium interface segregation of impurities, while also considering the influence of strain rate8. Cao et al. illustrated that the grain boundary embrittlement was caused by the synthetic effects of penetrating oxygen and stress concentration within the grain boundary13. As of the present moment, various strategies have been devised to mitigate ITE. Hou et al. identified that enhancing oxidation resistance through the addition of Cr can alleviate intermediate temperature embrittlement in CCAs. However, this approach might only be effective below 600° C.14. Instead of equiaxial grains, Cao et al. developed heterogenous columnar-grained microstructure, which exhibited high resistance to the intergranular fractures at 800° C. The microstructural stability at elevated temperatures may be a concern for this type of material due to the incomplete recrystallization15.
Accordingly, how to solve the intermediate temperature embrittlement while maintaining high strength and microstructural stability is still a tricky problem. The present invention addresses this need.
Accordingly, the present invention aims to address the challenges associated with chemical complex alloys (CCAs).
The present invention design one type of chemical complex alloy (CCA), which exhibits superb mechanical properties at temperatures from −196° C. to 1000° C. The intermediate temperature embrittlement is greatly inhibited by introducing serrated grain boundaries, while the strength is enhanced by formation of high-density multiscale L12 particles.
In a first aspect, the present invention provides a strong-yet-ductile chemically complex alloy over a wide temperature range, including 35-45 at. % of nickel (Ni), 15-25 at. % of cobalt (Co), 5-10 at. % of iron (Fe), 5-15 at. % of chromium (Cr), 5-10 at. % of aluminum (Al), 3-8 at. % of titanium (Ti), 0.5-3 at. % of tantalum (Ta), 0.3-2 at. % of niobium (Nb), 0.3-2 at. % of tungsten (W), 0.3-2 at. % of molybdenum (Mo), and one or more infinitesimal elements. The strong-yet-ductile chemically complex alloy forms one or more multi-scale L12 particles within a grain interior and exhibits serrated grain boundaries via controlling a heat treatment process. The Al, Ti, Ta and Nb facilitate the formation of the one or more multi-scale L12 particles, the W and Mo enhances a strength of a FCC matrix of the chemically complex alloy, and the one or more infinitesimal elements improve a cohesive strength of the serrated grain boundaries. The designed CCA displays distinctive microstructures comprising multiscale L12 particles and serrated grain boundaries. The carefully designed chemical composition together with the unique microstructures enables the CCA to exhibit exceptional mechanical properties at cryogenic, ambient, and elevated temperatures, complemented by outstanding high-temperature oxidation resistance.
In accordance with one embodiment, the one or more infinitesimal elements can be boron, zirconium, or hafnium. The one or more infinitesimal elements has an atomic percentage ranging from 0.01% to 0.15%.
In accordance with one embodiment, the wide temperature range is between −196° C. to 1,000° C.
In accordance with one embodiment, when tested at −196° C., the strong-yet-ductile chemically complex alloy achieves an ultimate tensile strength of at least 1500 MPa and along with a ductility of at least 35%. When tested at room temperature, the strong-yet-ductile chemically complex alloy achieves a yield strength of at least 700 MPa, an ultimate tensile strength of at least 1,300 MPa, and a ductility of at least 30%. When tested at a temperature between 600° C. to 900° C., a phenomenon of intermediate temperature embrittlement is inhibited by introducing the serrated grain boundaries. When tested at a temperature of 700° C., the strong-yet-ductile chemically complex alloy achieves a yield strength of at least 1,000 MPa along with a ductility of at least 20%. When tested at a temperature of 1,000° C., the strong-yet-ductile chemically complex alloy achieves an ultimate tensile strength of at least 300 MPa.
In a second aspect, the present invention provides a method for preparing a strong-yet-ductile chemically complex alloy over a wide temperature range. The steps include arc melting a mixture of raw materials having a purity >99.9 wt. % under a Ti-getter argon atmosphere to produce ingots; turning over and remelting the ingots for at least eight times to reduce composition segregation, and dropping the ingot into a copper mold to obtained as-cast samples; homogenizing the as-cast samples at 1000° C. to 1300° C. for 1 to 20 hours to obtained homogenized samples; furnace-cooling the homogenized samples to 400° C. to 800° C. at a cooling rate of 1° C./min to 15° C./min, followed by air cooling to room temperature to obtained first cooled samples; cold rolling the first cooled samples along a longitudinal direction with a reduction in thickness of 40% to 80%; recrystallizing cold-rolled samples at 1000° C. to 1300° C. for 1 to 10 minutes to obtained recrystallized samples; furnace-cooling the recrystallized samples to 400-800° C. at a cooling rate of 1-15° C./min followed by air cooling to room temperature to form second cooled samples with coarse primary L12 particles and serrated grain boundaries; and aging the second cooled samples at about 600° C. to 900° C. for 4 to 100 hours and cooling aged samples to room temperature by air cooling to obtain the strong-yet-ductile chemically complex alloy with nanoscale secondary L12 particles.
In accordance with one embodiment, the method further includes aging the chemically complex alloy.
Compared to existing technologies, the present invention offers the following major advantages:
Embodiments of the present invention are described in more detail hereinafter with reference to the drawings, in which:
The present invention will be described in detail through the following embodiments with appending drawings. It should be understood that the specific embodiments are provided for an illustrative purpose only, and should not be interpreted in a limiting manner. Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described.
The invention includes all such variation and modifications. The invention also includes all of the steps and features referred to or indicated in the specification, individually or collectively, and any and all combinations or any two or more of the steps or features. Other aspects and advantages of the invention will be apparent to those skilled in the art from a review of the ensuing description.
High-density multiscale ordered L12 particles strengthened CCAs with serrated grain boundaries are designed to overcome the above-mentioned critical issues. The present invention provides a strong-yet-ductile chemically complex alloy over a wide temperature range, including 35-45 at. % of nickel, 15-25 at. % of cobalt, 5-10 at. % of iron, 5-15 at. % of chromium, 5-10 at. % of aluminum, 3-8 at. % of titanium, 0.5-3 at. % of tantalum, 0.3-2 at. % of niobium, 0.3-2 at. % of tungsten, 0.3-2 at. % of molybdenum, and one or more infinitesimal elements. The strong-yet-ductile chemically complex alloy forms one or more multi-scale L12 particles within a grain interior and exhibits serrated grain boundaries via controlling a heat treatment process. The aluminum, titanium, tantalum and niobium facilitate the formation of the one or more multi-scale L12 particles, the tungsten and molybdenum enhances a strength of a FCC matrix of the chemically complex alloy, and the one or more infinitesimal elements improve a cohesive strength of the serrated grain boundaries.
The theory and method proposed in this invention can be utilized to develop new-generation structural materials with superior mechanical properties, particularly at elevated temperatures. Intermediate temperature embrittlement can be significantly mitigated through grain boundary serration (reducing local strain concentration and offering resistance against intergranular cracking) and by doping grain boundary strengthening elements (enhancing the cohesive strength of the grain boundaries). Additionally, the designed CCA is also suitable for industrialized production.
The fundamental principle behind CCAs design encompasses three key aspects: (1) incorporation of high-density multiscale L12 particles by doping elements Ti, Al, Ta, Nb; (2) enhancement of grain boundary resistance against crack propagation through serration; and (3) reinforcement of grain boundary cohesive strength by doping elements B, Zr, and Hf.
In one of the embodiments, the strong-yet-ductile chemically complex alloy contains approximately 15 at. % to approximately 25 at. % of cobalt. For example, the atomic percentage of cobalt in the alloy can be 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24% or 25%.
In one of the embodiments, the strong-yet-ductile chemically complex alloy contains approximately 5 at. % to approximately 10 at. % of iron. For example, the atomic percentage of iron in the alloy can be 5%, 6%, 7%, 8%, 9%, or 10%.
In one of the embodiments, the strong-yet-ductile chemically complex alloy contains approximately 5 at. % to approximately 15 at. % of chromium. For example, the atomic percentage of chromium in the alloy can be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14% or 15%.
In one of the embodiments, the strong-yet-ductile chemically complex alloy contains approximately 5 at. % to approximately 10 at. % of aluminum. For example, the atomic percentage of aluminum in the alloy can be 5%, 6%, 7%, 8%, 9%, or 10%.
In one of the embodiments, the strong-yet-ductile chemically complex alloy contains approximately 3 at. % to approximately 8 at. % of titanium. For example, the atomic percentage of titanium in the alloy can be 3%, 4%, 5%, 6%, 7%, or 8%.
In one of the embodiments, the strong-yet-ductile chemically complex alloy contains approximately 0.5 at. % to approximately 3 at. % of tantalum. For example, the atomic percentage of tantalum in the alloy can be 0.5%, 1%, 1.5%, 2%, 2.5%, or 3%.
In one of the embodiments, the strong-yet-ductile chemically complex alloy contains approximately 0.3 at. % to approximately 2 at. % of niobium. For example, the atomic percentage of niobium in the alloy can be 0.3%, 0.5%, 1%, 1.5%, or 2%.
In one of the embodiments, the strong-yet-ductile chemically complex alloy contains approximately 0.3 at. % to approximately 2 at. % of tungsten. For example, the atomic percentage of tungsten in the alloy can be 0.3%, 0.5%, 1%, 1.5%, or 2%.
In one of the embodiments, the strong-yet-ductile chemically complex alloy contains approximately 0.3 at. % to approximately 2 at. % of molybdenum. For example, the atomic percentage of molybdenum in the alloy can be 0.3%, 0.5%, 1%, 1.5%, or 2%.
In one of the embodiments, the strong-yet-ductile chemically complex alloy contains approximately 0.01 at. % to approximately 0.15 at. % of infinitesimal elements, such as boron, zirconium, or hafnium.
By meticulously controlling alloy compositions and the heat treatment process, high-density multiscale ordered L12 particles are embedded within the interior of the grains, while the grain boundaries display a serrated morphology. These distinctive phase structures and grain characteristics empower the newly engineered alloy to demonstrate exceptional tensile properties over a wide temperature range, encompassing cryogenic, ambient, and elevated temperatures, which is superior to most of the other type CCAs and Ni-based superalloys.
In one of the embodiments, as the temperature decreases from room temperature to about −196° C., both the tensile strength and ductility improve.
In one of the embodiments, when tested at room temperature, it achieved a high ultimate tensile strength of at least 1,300 MPa along with a ductility of at least 30%.
Preferably, when tested at room temperature, it achieved a high ultimate tensile strength of 1352 MPa along with a ductility of 35%.
In another embodiment, the CCA of the present invention demonstrates anomalous yielding behavior at 700° C., resulting in a substantial yield strength of at least 1,000 MPa, while maintaining a notable ductility of at least 20% without experiencing embrittlement.
Preferably, when tested at 700° C., it achieved a substantial yield strength of approximately 1043 MPa along with a ductility of 22%.
More importantly, the occurrence of intermediate temperature embrittlement, a significant reduction in ductility observed in the temperature range of 600 to 900° C. for most superalloys, can be mitigated by the presence of serrated grain boundaries.
In one of the embodiments, the CCA of the present invention exhibits exceptional high-temperature oxidation resistance up to 900° C.
In another embodiments, when tested at about 1000° C., the CCA of the present invention shows a superior strength of at least 300 MPa, without much work softening during tensile test.
Preferably, when tested at about 1000° C., the CCA of the present invention shows a superior strength of 336 MPa.
In a second aspect, the present invention also provides a method for preparing a strong-yet-ductile chemically complex alloy over a wide temperature range. The steps include arc melting a mixture of raw materials having a purity >99.9 wt. % under a Ti-getter argon atmosphere to produce ingots; turning over and remelting the ingots for at least eight times to reduce composition segregation, and dropping the ingot into a copper mold to obtained as-cast samples; homogenizing the as-cast samples at 1000° C. to 1300° C. for 1 to 20 hours to obtained homogenized samples; furnace-cooling the homogenized samples to 400° C. to 800° C. at a cooling rate of 1° C./min to 15° C./min, followed by air cooling to room temperature to obtained first cooled samples; cold rolling the first cooled samples along a longitudinal direction with a reduction in thickness of 40% to 80%; recrystallizing cold-rolled samples at 1000° C. to 1300° C. for 1 to 10 minutes to obtained recrystallized samples; furnace-cooling the recrystallized samples to 400-800° C. at a cooling rate of 1-15° C./min followed by air cooling to room temperature to form second cooled samples with coarse primary L12 particles and serrated grain boundaries; and aging the second cooled samples at about 600° C. to 900° C. for 4 to 100 hours and cooling aged samples to room temperature by air cooling to obtain the strong-yet-ductile chemically complex alloy with nanoscale secondary L12 particles.
The following examples illustrate the present invention and are not intended to limit the same.
Aging treatment is a heat treatment process that involves holding the alloy at a certain temperature for a specific duration, causing changes in its crystal structure and phases to alter its properties and characteristics. Chemical complex alloys typically consist of multiple elements, and their interactions and bonding result in intricate microstructures and properties. After undergone aging treatment, the microstructures of aged CCA were first characterized by Scanning electron microscopy (SEM, FEI, Scios, 10 kV, 0.4 nA) in the secondary electron (SE) mode. Phase constitution of the aged CCA was determined by the X-ray diffraction with Cu Kα radiation and a step size of 0.02° (XRD, Bruker AXS D2, operated at 30 kV and 10 mA). Electron backscatter diffraction (EBSD) maps were acquired using an EDAX Velocity camera equipped on a FEI Scios microscope at an accelerating voltage of 20 kV and current of 13 nA. Samples for the SEM, EBSD, and XRD experiments were first mechanically polished with diamond suspension, and then electrolytic polished in a mixed solution of C2H6O:HNO3=4:1 for 5 s with a direct voltage of 20 V at −40° C. temperature. Microstructural feature, elemental distribution and crystal structure were further characterized using Cs-corrected transmission electron microscopy (CSTEM, FEI Titan Themis G2, operated at 300 kV) equipped with energy disperse spectroscopy (EDS) and selected area electron diffraction (SAED). The samples used for TEM test were first mechanically polished to about 40 μm using SiC grinding paper, and then punched into 3-mm-diameter discs. A precision ion polishing system (PIPS II, Model 695, Gatan) was used to mill these discs to a thickness of electron transparency (4 keV, ±4°). To further determine the chemical composition of the precipitates precisely, three-dimensional atom probe tomography (3DAPT, CAMEACA LEAP 5000 XR) experiments were conducted in voltage mode at 70 K, a pulse repetition rate of 200 kHz, a pulse fraction of 20%, and an evaporation detection rate of 0.2% atom per pulse. AP Suite 6.1 workstations were used reconstructing the 3D distribution of atoms. Needle-shaped samples for 3D APT test were prepared via focused ion beam/scanning electron microscope (FIB/SEM, FEI Scios).
Tensile tests were conducted on a Material Testing System (MTS) machine at cryo (−196° C.), room (25° C.) and elevated temperatures with a constant strain rate of 1×10−3 s-1. Flat dog-bone-shaped tensile samples with a gauge length of 12.5 mm and a cross-section dimension of 3.2×1.7 mm2 prepared by ProtoMAX Abrasive Waterjet Cutter. Before tensile tests, the samples were ground to 3000-grit finish using SiC grinding papers. At least three samples were tested for each condition to guarantee the data reproducibility. After tensile tests, the deformation mechanisms were determined by collaborative using SEM, EBSD, and TEM methods.
The fabrication process of the CCA primarily involves the following steps: First, arc melting a mixture of high-purity raw materials (purity >99.9 wt. %) under a Ti-getter argon atmosphere. Arc melting involves the process of heating and melting materials by generating an arc discharge (electric arc) between two electrodes through the application of high current and voltage. The ingot was turned over and remelted eight times to reduce composition segregation, and then dropped into a rectangular-section copper mold measuring 5×10×100 mm3. The as-cast samples were first solution treated at 1200° C. for 2 hours, and then furnace cooled to 800° C. at a cooling rate of 4° C./min followed by air cooling to room temperature. After that, the samples were cold rolled along a longitudinal direction with a reduction in thickness of 65%. The cold-rolled samples were recrystallized at 1200° C. for 2 minutes, and then furnace cooled to 800° C. at a cooling rate of 4° C./min followed by air cooling to room temperature. This process enables the formation of coarse primary L12 particles and serrated grain boundaries during the slow cooling rate. Finally, the recrystallized samples were aged at about 800° C. for 24 hours and then cooled to room temperature by air cooling to introduce nanoscale secondary L12 particles.
Referring to
The aging process at an intermediate temperature of 800° C. contributed to the formation of secondary spherical nanoprecipitates. The average particle sizes for the primary and secondary precipitates were approximately 1000 nm and 75 nm, respectively. Meanwhile, certain elongated precipitates are distributed along the grain boundaries, potentially hindering the movement of grain boundaries and thus contributing to the formation of serrated grain boundaries (GB) during the gradual cooling process.
The morphology and crystal structure of aged CCA was further confirmed. Referring to
In
To determine the chemical composition of the FCC matrix and the multiscale precipitates, STEM-EDS mapping was performed.
As depicted in
According to the aforementioned experimental data, the main composition components of CCAs include Ni, Co, Fe, Cr, Al, Ti, Ta, Nb, W, Mo, B, Zr, and Hf, with their atomic percentages respectively shown in Table 1.
Preferably, the designed CCA consists of 41.98 at. % of Ni, 23.7 at. % of Co, 8 at. % of Fe, 10 at. % of Cr, 8.6 at. % of Al, 5 at. % of Ti, 1 at. % of Ta, 0.5 at. % of Nb, 0.5 at. % of W, 0.5 at. % of Mo, 0.1 at. % of B, 0.02 at. % of Zr, and 0.1 at. % of Hf.
However, due to the limited accuracy of the EDS method, it was challenging to precisely quantify the complex chemical composition of the phases in the aged CCA, especially for the nanoscale secondary L12 and FCC nanoparticles within the primary L12 phase.
Accordingly, 3DAPT (Three-Dimensional Atom Probe Tomography) experiments were conducted to further accurately quantify the specific chemical composition of each phase in the aged CCA. 3DAPT experiments are an advanced atomic probe layer-by-layer imaging technique used to study the atomic-scale structure and composition of materials. It allows researchers to reconstruct the atomic positions and composition of materials in three-dimensional space, providing high-resolution atomic-level information. In 3DAPT experiments, an atomic probe tip is utilized for probing. This tip is subjected to a strong electric field, causing atoms within a tiny region to be sequentially dissociated and flown onto a detector. By tracking the flight of these atoms, their flight times can be determined, inferring their atomic positions. Through this process, 3DAPT can reconstruct the atomic positions of materials in three-dimensional space, resulting in atomic-scale three-dimensional images.
The distribution of atomic elements and the corresponding proximity histogram across the precipitate/matrix interfaces were presented in
Referring to
When the temperature dropped from RT to −163° C., both the tensile strength (YS, UTS), and ductility were enhanced, resulting in a higher UTS of 1500 MPa and a slight increase in ductility to 39%.
In
It was worth noting that the aged CCA exhibited unique tensile properties at elevated temperatures. When the deformation temperatures ranged from 400 to 600° C., the aged CCA showed exceptional work-hardening abilities with high fracture elongations exceeding 20%.
Interestingly, an anomalous yielding behavior occurred at 700° C., resulting in a high yield strength of 1045 MPa. More importantly, the aged CCA did not exhibit severe intermediate temperature embrittlement at 700-800° C., which was a challenging issue observed in various alloys, including Al alloys, steel, and Ni-based superalloys.
When deformed at 800° C., the aged CCA was able to maintain a high ductility of 16.2%. In contrast, such high temperature caused most nickel or cobalt-based superalloys to exhibit severe brittle characteristics. Moreover, when deformed above 900° C., the ductility was improved, accompanied by a decrease of tensile strength. From above results, it was evident that the aged CCA showed superior ductility compared to those alloys, particularly at intermediate temperatures in a range of 600-900° C.
Meanwhile, the aged CCA also exhibited excellent tensile strength across the entire temperature range, surpassing that of the commercial Ni-based Inconel 718 alloy, particularly at temperatures above 600° C. At a temperature of 1000° C., the aged CCA was still able to maintain a high strength of approximately 336 MPa, whereas the ultimate tensile strength (UTS) of Inconel 718 dropped to 67 MPa at the same temperature (
Referring to
The formation of micro-cracks along the grain boundaries decreased the flow stress, resulting in strain softening when deformed above 700° C. With a further temperature increase to 800° C., additional microcracks were observed on the fractured surface. Apart from the presence of ductile dimples, flat dissociation surfaces were also evident, indicating a slight transition from a ductile to a brittle fracture mode (
In summary, the present invention achieves a Ni-rich CCA with excellent mechanical properties over a wide temperature range (−196 to 1000° C.) through alloy design and thermomechanical control. The designed CCA displays distinctive microstructures comprising multiscale L12 particles and serrated grain boundaries. The temperature-dependent mechanical responses of these CCAs are closely linked to the deformation mechanisms activated at varying temperatures.
Throughout this specification, unless the context requires otherwise, the word “comprise” or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers. It is also noted that in this disclosure and particularly in the claims and/or paragraphs, terms such as “comprises”, “comprised”, “comprising” and the like can have the meaning attributed to it in U.S. Patent law; e.g., they allow for elements not explicitly recited, but exclude elements that are found in the prior art or that affect a basic or novel characteristic of the present invention.
Furthermore, throughout the specification and claims, unless the context requires otherwise, the word “include” or variations such as “includes” or “including”, will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.
References in the specification to “one embodiment”, “an embodiment”, “an example embodiment”, etc., indicate that the embodiment described can include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.
The term “at. %” stands for “atomic percent,” which is a unit used to describe the relative content of chemical components. In chemistry and materials science, atomic percent represents the percentage of a certain element's atoms in a compound or mixture, calculated based on the number of atoms of that element. It can be used to describe the relative proportions of different elements in solid materials, alloys, solutions, and more. Atomic percent provides a more precise way to indicate the content of elements, especially in cases involving complex chemical compositions and alloy formulations, as it accurately reflects the relative contributions of elements.
Other definitions for selected terms used herein may be found within the detailed description of the present invention and apply throughout. Unless otherwise defined, all other technical terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which the present invention belongs.
It will be appreciated by those skilled in the art, in view of these teachings, that alternative embodiments may be implemented without undue experimentation or deviation from the spirit or scope of the invention, as set forth in the appended claims. This invention is to be limited only by the following claims, which include all such embodiments and modifications when viewed in conjunction with the above specification and accompanying drawings.
Chemical complex alloys (CCAs) offer high flexibility in tuning properties to meet requirements under extreme environments. Considering the comprehensive excellent properties at cryogenic, ambient, and elevated temperatures, the potential applications of the designed CCA include. but are not limited to:
In particular, the most potential markets for the present invention are aero-engines and gas turbines. For instance, in advanced aero-engines, superalloys constitute 40% to 60% of the total engine weight. The requirement for high-temperature alloy raw materials to power aero-engines was projected to reach 20,000 tons in the year 2020. Nevertheless, as aerospace technology advances, a greater thrust-to-weight ratio becomes essential, placing more demanding stress on superalloys. Under these conditions, failure could arise due to the prevalent intermediate temperature embrittlement of superalloys. In contrast to conventional superalloys, the prepared CCA in the present invention demonstrates enhanced strength and ductility, particularly under elevated temperatures. Consequently, this engineered CCA holds significant promise for substituting certain traditional Ni-based superalloys, leading to energy conservation and enhanced safety.
