变质和热处理对Al-20%Si合金组织和力学性能的影响  

Influences of Modification and Heat Treatment on Microstructure and Mechanical Properties of Hypereutectic Al-20%Si Alloy

作　　者：刘扭参[1,2] 刘栓江[3] 刘忠侠[2] 

机构地区：[1]河南工程学院数理科学系,河南郑州451191 [2]郑州大学物理工程学院材料物理教育部重点实验室,河南郑州450052 [3]安阳工学院理学部,河南安阳455000

出　　处：《铸造技术》2009年第8期1022-1025,共4页Foundry Technology

摘　　要：采用P-Cu中间合金和Al-10%RE中间合金对过共晶Al-20%Si合金进行变质处理,研究了变质和热处理对Al-20%Si合金组织和力学性能的影响。结果表明,合金经变质和热处理后,初晶硅尺寸得到明显细化,共晶硅由长针状变为细小的颗粒状,并且其抗拉强度、伸长率、硬度、冲击韧度得到明显改善,特别是当采用复合变质和T6工艺联合处理时,合金的抗拉强度、伸长率、硬度、冲击韧度长分别提高到306MPa、0.48%、166.7HB和11.0098J/cm2,比未变质铸态合金分别提高了27%、54.8%、37.3%和17.7%。原因在于复合变质与T6处理增加了基体的强度,抑制了裂纹的萌生和扩展。The hypereutectic Al-20% Si alloys were modified with P-Cu alloys and Al-Re alloys and treated with T6 heat treatment process. The microstructures and mechanical properties were investigated. The results show that the shape of Si particles is improved obviously by the complex modification of P and RE and T6 process. The size of primary Si particles is obviously decreased. The eutectic Si particles are changed to global or short bar shape. The tensile strength, elongation, hardness and impact toughness are improved. Especially when treated with combination .of complex modification and T6 heat treatment process, the tensile strength, elongation, hardness and impact toughness increased to 306 MPa,0.48%,166.7 HB and 11. 009 8 J/cm^2, which is 27% ,54.8%, 37.3% ,17.7% of that unmodified as-cast alloys. It can be explained that the complex modification of Si particles and T6 process increase the strength of matrix and restrain initiation and growth of crack.

关 键 词：过共晶铝硅合金 变质 T6热处理 力学性能 

分 类 号：TG146.21[一般工业技术—材料科学与工程]