热处理工艺对AuAgCu35-5合金片材力学性能的影响

Effects of Heat-treatment Process on Mechanical Properties of AuAgCu35-5 Alloy Sheet

采用真空感应熔炼、冷加工成型技术制备AuAgCu35-5合金片材,研究不同热处理工艺对AuAgCu35-5合金片材力学性能的影响。结果表明:AuAgCu35-5合金片材在经350℃/1 h热处理时硬度达到最大,400℃/1 h合金的硬度比对应不同加工率下的硬态试样的平均低6.2%,平均硬度为201.9 HV;室温拉伸试验的应力-应变曲线表明,屈服强度和抗拉强度均随着热处理温度的升高而降低,400℃/1 h的抗拉强度、屈服强度和伸长率均较高;不同热处理工艺下的拉伸断口表现出明显的塑性断裂的特点,350℃/1 h的断口有韧性和脆性混合断裂的特征,400℃/1 h的断口韧窝较浅且较为均匀,韧窝呈圆形或椭圆形,断口相对于300℃/1 h和350℃/1 h的较为平整,塑性较好。

AuAgCu35-5 alloy sheet was prepared through vacuum induction melting and subsequent cold forming technology. The effects of different heat treatment processes on the mechanical properties of AuAgCu35-5 alloy sheet were studied. The results show that the AuAgCu35-5 alloy sheet reaches the maximum hardness after heat treatment at 350 ℃/1 h,the hardness of 400 ℃/1 h alloy is 6.2% lower than that of the hard samples under different processing rates, and the average hardness is 201.9 HV. The stress-strain curve of tensile test at room temperature shows that the yield strength and tensile strength decrease with the increase of heat treatment temperature, and the tensile strength, yield strength and elongation at 400℃/1 h are also better. The tensile fracture surface under different heat treatment processes shows the characteristics of plastic fracture. The fracture surface at 350 ℃/1 h has the characteristics of ductile and brittle mixed fracture. The dimple at 400 ℃/1h is shallow and uniform, and the dimple is round or oval. The fracture surface is relatively flat and plastic compared with that at 300 ℃/1 h and 350 ℃/1 h.