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.
出处
《铸造技术》
CAS
北大核心
2009年第8期1022-1025,共4页
Foundry Technology
关键词
过共晶铝硅合金
变质
T6热处理
力学性能
Hypereutectic AI-Si alloy
Modification
T6 heat treatment
Mechanical property
