ZL114A铝硅合金微观疏松的HIP工艺处理

Effects of HIP process on microstructure and mechanical properties of micro-porosity in ZL114A alloy

采用光学显微镜OM、扫描电镜SEM、WDW-100 KN万能拉伸试验机、PLA30050疲劳试验机,结合三因素三水平正交试验,研究了不同等级微观疏松冶金缺陷经热等静压处理(HIP)工艺处理后的微观组织与力学性能。结果表明,HIP工艺处理温度对Q值(合金材料综合性能数值)影响最高,其次为HIP压力与时间。ZL114A合金Ⅲ级微观疏松冶金缺陷经540℃与140 MPa下HIP处理4 h后,合金材料的抗拉强度、屈服强度、延伸率、布氏硬度与轴向疲劳寿命分别增至340 MPa、280 MPa、8%、125HBS和4.1×105,综合力学性能Q值达到475.45。综合工艺成本与使用效果考虑,ZL114A合金优先选用540℃、140 MPa与2 h的HIP工艺参数。相同HIP工艺参数下,与Ⅲ级微观疏松冶金缺项相比,Ⅰ级与Ⅱ级微观疏松冶金缺陷区域经HIP处理后的Q值分别提升5.1%与2.4%;Ⅳ级与Ⅴ级微观疏松冶金缺陷区域分别降低15.98%和25.61%。

The microstructure and mechanical properties of different grades of micro-porosity are studied by optical microscope, scanning electron microscopy, WDW-100 KN universal tensile testing machine, and PLA30050 fatigue testing machine, together with the orthogonal test with three factors and levels. The results show that the most important impact parameter on the HIP process is temperature, followed by pressure and time. The tensile strength, yield strength, elongation, Brinell hardness, axial fatigue life and Q value of ZL114 A alloy within the micro-porosity of grade III are increased to 340 MPa, 280 MPa, 8%, 125 HBS, 4.1×105and 475.45, respectively after the HIP process under 540℃, 140 MPa and 4 h conditions. Cconsidering both the process cost and effect, the optimal parameters of HIP process are 540℃,140 MPa and 2 h. Compared with the micro-porosity of grade III, the Q values of grade I and grade II are increased by 5.1% and 2.4%,respectively after the HIP process, whereas the Q values of grades IV and V are decreased by 15.98% and 25.61%, respectively.