Sn含量对2011铝合金棒材显微组织、切削与力学性能的影响

Effect of Sn Content on Microstructure,Machinability and Mechanical Properties of 2011 Aluminum Alloy Bar

以Sn、Bi替代Pb,制备无铅易切削2011铝合金棒材.利用光学显微镜、扫描电子显微镜、高速车床和拉伸试验机,研究了Sn含量对2011铝合金棒材显微组织、切削性能和拉伸力学性能的影响.结果表明:Sn含量为0.2%时,Sn以SnBi共晶相形式存在于铝合金棒材中.Sn含量超过0.2%时,Sn以单质Sn相和SnBi共晶相形式存在于铝合金棒材中.Sn含量越高,单质Sn相和SnBi共晶相的数量越多,铝合金棒材的切削性能越好,车屑长度越短,但拉伸力学性能略有下降.

The free cutting 2011 aluminum alloy bars without lead were prepared by substituting Sn and Bi for Pb.The effect of Sn content on microstructure,machinability and mechanical properties of 2011 aluminum alloy bar were studied by metallo-graphic microscope,scanning electron microscope,tensile testing machine and high-speed lathe.The results showed that when the Sn content was 0.2%,Sn mainly existed in the form of SnBi eutectic phase in aluminum alloy bars.When the content of Sn exceeded 0.2%,Sn existed in the form of Sn phase and SnBi eutectic phase.The higher the Sn content was,the more the a-mount of Sn phase and SnBi eutectic phase were,and the better the machinability of aluminum alloy bar was.However,the tensile strength and the elongation of aluminum alloy bar decreased slightly with the increase of Sn content.