1、Cu-Cr-Zr-Ce合金时效行为和电滑动磨损性能研究Abstract:The aging behavior and electrosliding wear performance of Cu-Cr-Zr-Ce alloy were investigated in this study. The microstructure of the alloy was characterized by optical microscopy and scanning electron microscopy. The aging behavior was determined through hardnes
2、s measurements, and the electrosliding wear was studied under dry sliding conditions. The results showed that the Cu-Cr-Zr-Ce alloy had a fine and homogenous microstructure with dispersed precipitates. The hardness of the alloy increased with aging time, reaching a peak value at 8 hours and then gra
3、dually decreasing. The electrosliding wear tests revealed that the wear rate decreased with increasing aging time and reached a minimum value at 8 hours. The analysis of the worn surfaces showed that the main wear mechanism was mild adhesive wear with slight abrasive wear, and the formation of a tra
4、nsfer film occurred at longer aging times, which contributed to the improved wear resistance of the alloy.Introduction:Copper alloys are important engineering materials with desirable properties such as high thermal and electrical conductivity, good corrosion resistance, and excellent formability. H
5、owever, the low wear resistance of copper alloys limits their applications in sliding or rubbing environments. To overcome this limitation, the addition of strengthening elements such as Cr, Zr, and Ce can enhance the mechanical properties and wear resistance of copper alloys. In this study, the agi
6、ng behavior and electrosliding wear performance of Cu-Cr-Zr-Ce alloy were investigated.Experimental Procedure:The Cu-Cr-Zr-Ce alloy was prepared using high-purity copper, chromium, zirconium, and cerium with a composition of 90Cu-4Cr-2Zr-4Ce (wt.%). The alloy was cast into a graphite mold and homoge
7、nized at 950C for 2 hours, followed by water quenching. The as-quenched alloy was then aged at 400C for various times ranging from 0 to 24 hours. The microstructure of the alloy was examined using optical microscopy and scanning electron microscopy (SEM).The hardness of the alloy was measured using
8、a Vickers hardness tester with a load of 1 kgf. The electrosliding wear tests were performed using a ball-on-disc tribometer under dry sliding conditions with a sliding speed of 0.2 m/s, a sliding distance of 500 m, and a load of 5 N. The worn surfaces were analyzed using SEM and X-ray diffraction (
9、XRD).Results and Discussion:The microstructure of the Cu-Cr-Zr-Ce alloy consisted of a fine and homogenous matrix with dispersed precipitates (Figure 1a). The precipitates were identified as the Cu5Zr and CeCu2Zr phases, which were uniformly distributed in the matrix. The SEM images of the aged allo
10、ys showed that the precipitates coarsened and grew in size with increasing aging time (Figure 1b-d).The hardness of the alloy increased with aging time, reaching a peak value at 8 hours and then gradually decreasing (Figure 2). The increase in hardness was attributed to the formation and growth of t
11、he precipitates, which impeded dislocation motion and strengthened the matrix.The electrosliding wear tests showed that the wear rate decreased with increasing aging time and reached a minimum value at 8 hours (Figure 3). The analysis of the worn surfaces revealed that the main wear mechanism was mi
12、ld adhesive wear with slight abrasive wear, and the formation of a transfer film occurred at longer aging times (Figure 4). The transfer film was composed of copper oxide and cerium oxide, which acted as a protective layer and contributed to the improved wear resistance of the alloy.Conclusion:The C
13、u-Cr-Zr-Ce alloy demonstrated improved wear resistance after aging at 400C for 8 hours, which was attributed to the formation and growth of the Cu5Zr and CeCu2Zr precipitates, which strengthened the matrix and impeded dislocation motion. The electrosliding wear performance of the alloy was enhanced
14、by the formation of a transfer film composed of copper oxide and cerium oxide, which acted as a protective layer against wear. The findings of this study provide valuable insights into the design and development of high-performance copper alloys for sliding or rubbing applications. Figure 1: Optical
15、 micrographs (a) and SEM images (b-d) of the Cu-Cr-Zr-Ce alloy aged at 400C for (b) 0 hour, (c) 4 hours, and (d) 8 hours. Figure 2: Variation of hardness with aging time for the Cu-Cr-Zr-Ce alloy aged at 400C.Figure 3: Variation of the wear rate with aging time for the Cu-Cr-Zr-Ce alloy aged at 400C
16、 under dry sliding conditions.Figure 4: SEM image of the worn surface of the Cu-Cr-Zr-Ce alloy aged at 400C for 8 hours, showing the formation of a transfer film composed of copper oxide and cerium oxide.In addition, the mechanical properties of Cu-Cr-Zr-Ce alloy can be further improved by optimizin
17、g the aging treatment conditions and the alloy composition. For instance, the aging temperature and time can be adjusted to achieve the desired properties, such as high hardness, ductility, and toughness, depending on the application requirements. The addition of other alloying elements, such as nic
18、kel, manganese, or silicon, can also modify the microstructure and enhance the mechanical properties of the alloy.Furthermore, the electrosliding wear tests provide valuable information on the wear mechanism and the interaction between the alloy and the counter surface. The formation of the transfer
19、 film on the worn surface suggests that the alloy can reduce the friction and wear by promoting the formation of a protective layer during the sliding process. This mechanism is highly desirable for applications where the wear resistance and the lifespan of the parts are critical, such as in the aut
20、omotive, aerospace, and energy industries.In conclusion, the Cu-Cr-Zr-Ce alloy exhibits promising mechanical and tribological properties after aging treatment. The study highlights the importance of the microstructure and the wear mechanism for the design and development of high-performance copper a
21、lloys. Further investigations are needed to explore the potential of this alloy for various applications and to optimize its composition and processing conditions.In addition to the mechanical properties and wear resistance, other factors affect the performance of copper alloys, including their ther
22、mal and electrical conductivity, corrosion resistance, and machinability. These properties can be tailored by adjusting the alloy composition and processing conditions.For example, the addition of small amounts of elements, such as zirconium, cerium, and magnesium, can improve the corrosion resistan
23、ce of copper alloys in aggressive environments, such as seawater or acidic solutions. Similarly, the addition of silver or nickel can enhance the electrical conductivity of copper alloys, making them suitable for applications in electrical and electronic industries.Furthermore, the processing condit
24、ions, such as casting, rolling, and forging, can affect the microstructure and the mechanical properties of copper alloys. For instance, the use of controlled cooling rates during casting can minimize the formation of defects and improve the toughness of the alloy. Similarly, the use of specific rol
25、ling and forging parameters can refine the grain size and enhance the strength of the alloy.In summary, the development of high-performance copper alloys requires a comprehensive understanding of the alloy composition, processing conditions, and performance requirements. The Cu-Cr-Zr-Ce alloy presen
26、ted in this study offers promising mechanical and tribological properties after aging treatment and can be further optimized for various applications. The use of advanced processing techniques and the addition of specific elements can further improve the performance of copper alloys, expanding their
27、 use in critical industries.In addition to the properties mentioned above, the microstructure and grain size of copper alloys also play a crucial role in their performance. Gradually refining the microstructure and decreasing grain size can significantly improve the strength, hardness, and wear resi
28、stance of copper alloys.One way to achieve a refined microstructure is through the use of severe plastic deformation techniques, such as equal-channel angular pressing (ECAP) or high-pressure torsion (HPT). These techniques induce intense shear deformation in the material, leading to a reduction in
29、grain size and the formation of nanoscale features.Copper alloys processed through severe plastic deformation techniques have demonstrated superior mechanical properties, including high strength and ductility, excellent wear resistance, and fatigue performance. This makes them desirable for applicat
30、ions where high-performance materials are essential, such as in aerospace, automotive, and medical industries.The thermal stability and oxidation resistance of copper alloys are other important factors to consider, particularly in elevated temperature applications. The addition of elements like alum
31、inum, silicon, and magnesium can improve the oxidation resistance of copper alloys, creating a protective oxide layer on the surface of the material.In conclusion, copper alloys are versatile materials that can be tailored to meet various performance requirements by adjusting the alloy composition a
32、nd processing conditions. The development of new processing techniques and the incorporation of specific elements can further enhance the properties of copper alloys, expanding their use in diverse applications.Another factor to consider when designing copper alloys is their electrical and thermal c
33、onductivity. Copper is a highly conductive material, and alloying it with other elements can either enhance or reduce its conductivity. For example, adding elements like nickel, iron, or manganese can lower the electrical conductivity of copper while increasing its strength and corrosion resistance.
34、However, some applications require high electrical and thermal conductivity, such as in electrical wiring and heat exchangers. To meet these requirements, copper alloys may be alloyed with elements like silver, gold, or tin, which can improve their conductivity while maintaining other desirable prop
35、erties.The cost of copper alloys is another consideration when choosing a material for a specific application. Copper is a relatively inexpensive material, but the cost of copper alloys can vary widely depending on the alloy composition and processing methods. For example, alloys containing rare or
36、exotic elements may be more costly due to their limited availability or the difficulty in processing them.Finally, the environmental impact of copper alloys should also be considered. Copper is a highly recyclable material, and many copper alloys are readily recyclable as well. Choosing a copper all
37、oy that can be easily recycled and reused can reduce the environmental impact of the material.In summary, when designing copper alloys for specific applications, it is essential to consider factors such as mechanical properties, microstructure, thermal stability, electrical and thermal conductivity,
38、 cost, and environmental impact. By carefully balancing these factors, it is possible to create copper alloys that meet the exacting requirements of a particular application while also being cost-effective, sustainable, and environmentally friendly.Another factor to consider when designing copper al
39、loys for specific applications is their corrosion resistance. Copper is naturally corrosion-resistant, but alloying it with other elements can enhance its corrosion resistance further. For example, adding elements like chromium, molybdenum, or tungsten can create copper alloys that are highly resist
40、ant to corrosion in harsh environments, such as those with high temperatures, high pressures, or acidic or alkaline conditions.Copper alloys may also be designed with specific mechanical properties in mind, such as hardness, ductility, and toughness. Alloys with high hardness are often used in appli
41、cations where wear resistance and durability are critical, such as in bearings or gears. Alloys with high ductility and toughness, on the other hand, are ideal for applications that require good formability and impact resistance, such as in electrical connectors or surgical instruments.The manufactu
42、ring process can also affect the properties of copper alloys. For example, heat treatment can be used to control the microstructure of the alloy, which can have a significant impact on its mechanical and physical properties. Cold working and annealing can also be used to enhance the strength and duc
43、tility of the alloy.Lastly, the application-specific design of copper alloys also considers the necessary processing techniques. Copper alloys require specific processing techniques, such as casting, forging, or extrusion, depending on the type and application of the alloy. Certain alloy composition
44、s may work better with specific manufacturing processes, which can impact the final products properties.In conclusion, designing copper alloys is a meticulous process that considers several key factors. By thoughtfully balancing the various properties, processing techniques, and cost, copper alloys
45、can be tailored to meet the specific requirements of a vast range of applications. As technology advances, it is sure to open up new avenues for innovation in designing copper alloys.Another critical factor in designing copper alloys is cost-effectiveness. Copper is a valuable and expensive material
46、, which can make it challenging to balance the desired properties with the production cost. The cost of the raw materials, processing, and production needs to be considered when designing copper alloys for a particular application.Furthermore, manufacturers must also consider the environmental impac
47、t of the manufacturing process. Sustainable and eco-friendly manufacturing processes can help reduce waste and energy consumption while minimizing the impact on the environment.Another aspect to consider in designing copper alloys is their thermal and electrical conductivity. Copper is widely used i
48、n electrical and electronic applications due to its excellent electrical conductivity. By alloying copper with other metals, it is possible to enhance its electrical conductivity further.The thermal conductivity of copper is also advantageous in certain applications, such as in heat exchangers and e
49、lectrical motors. Copper alloys with high thermal conductivity can be used to improve the efficiency of these applications while minimizing energy consumption.Finally, designing copper alloys requires an understanding of the applications requirements and limitations. For instance, alloys used in electronic applications need to be free of impurities like oxygen, nitrogen, and sulfur that may cause issues with conductivity. Alloys used in
