Al-Cu-Mn铸造合金的高温力学性能研究

Research of High Temperature Mechanical Properties for Al-Cu-Mn Casting Alloy

研究了不同温度条件下的Al-Cu-Mn合金力学性能,并采用金相、SEM、EDS手段分析了不同温度下试样的微观组织。研究结果表明:随着温度的升高,合金抗拉强度从468MPa降到395MPa,而伸长率也从2.8%降到1.5%。通过合金的金相可知,合金力学性能的降低是高温第二相质点发生偏聚导致的。结合SEM、EDS测试,结果表明,合金在高温产生了短暂的过时效,影响了第二相质点的凝聚状态。同时拉伸温度对试样断裂形式也有明显影响,断口主要呈现沿晶断裂,而在常温拉伸时,断裂形式以穿晶断裂为主。

Al-Cu-Mn alloy mechanical properties in the different temperature condition were studied. The microstructure of sample in different temperature was analyzed with metallograph, SEM, EDS. Results show that with the rise of temperature, alloy tensile strength is from 468 MPa to 395 MPa, and elongation rate is from 2.8% to 1.5%. Through the analysising metallograph of alloy, cause on decrease of mechanical properties of alloy was known, which was the second phase particle in high temperature happened segregation. Combined with SEM and EDS test, the results show that alloy produces a short overageing in high temperature; the particle condensed state of the second phase is affected. At the same time, stretching temperature on the fracture mode also has significant effect, but the main fracture presents the intergranular fracture. In normal temperature tensile, fracture mode is transgranular cracking primarily.