快速凝固/粉末冶金Al-20Si-7.5Ni-3Cu-1Mg-0.25Fe合金的显微组织与力学性能  

Microstructure and Mechanical Properties of Al-20Si-7.5Ni-3Cu-1 Mg-0.25Fe Alloy Prepared by Rapidly Solidified Powder Metallurgy

作　　者：唐鹏钧[1] 何晓磊[1] 王兴元[1] 李沛勇[1] 

机构地区：[1]北京航空材料研究院,北京100095

出　　处：《航空材料学报》2013年第3期12-17,共6页Journal of Aeronautical Materials

摘　　要：采用快速凝固/粉末冶金工艺制备Al-20Si-7.5Ni-3Cu-1Mg-0.25Fe合金挤压棒材,通过OM,SEM,TEM,XRD和拉伸试验等手段研究挤压态和T6态合金的显微组织及力学性能。结果表明:挤压态和T6态合金的主要组成相均为α(Al),β(Si),Al3Ni,Al3Ni2,Al7Cu4Ni和Al4Cu2Mg8Si7。挤压态合金中块状Si相平均尺寸约为2.4μm,且带有明显尖角;T6热处理后,块状Si相发生粗化和球化现象,粗化后其平均尺寸约为3.2μm。T6态合金的室温抗拉强度和屈服强度分别为490MPa和415MPa,硬度达到91.3HRB。挤压态和T6态合金的拉伸断口平整,均属脆性断裂,且断口出现由Si相破裂后形成的小平面。The A1-20Si-7.5Ni-3Cu-lMg-0.25Fe alloy was prepared by rapidly solidified powder metallurgy process. The microstructures and mechanical properties of extruded and T6-treated alloys were investigated by OM, SEM, TEM, XRD and tensile test. The results show that both of the extruded and T6-treated alloys are constitutive of a （A]）, 13 （Si）, A13Ni, AI3Ni2, A17Cu4Ni and A14Cu2MgsSi7. The mean size of Si phases with sharp edges is 2.4μm in the extruded alloy, while it is 3.2μm in the T6 treated alloy after coarsening and spheroidizing. At room temperature, the ultimate tensile strength, yield strength and Rockwell hardness of T6-trea- ted alloy reach up to 490MPa, 415MPa and 91.3HRB respectively. It has been found that the fracture surfaces of these alloys aeat and composed of small facets of Si phases, which indicate that the alloy fracture appearsed belongs to the brittle pattern.

关 键 词：快速凝固 粉末冶金 高硅铝合金 显微组织 力学性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程]