论文部分内容阅读
采用光学显微镜、扫描电镜等研究了稀土Yb对A356铝合金显微组织与力学性能的影响。结果表明,Yb显著细化了A356合金中α-Al的晶粒尺寸,二次枝晶间距从41μm减小到30μm。共晶Si组织由粗大的针状或板条状细化为纤维状。添加Yb的A356铝合金中生成了一种新的AlSiYb金属间化合物。随着Yb含量的增加,A356铝合金的力学性能先增大后减小,当Yb含量为0.2%时,合金的力学性能达到最大值,其抗拉强度为195 MPa,伸长率为4.8%。
The effects of rare earth Yb on the microstructure and mechanical properties of A356 aluminum alloy were investigated by optical microscope and scanning electron microscope. The results showed that Yb remarkably refined the α-Al grain size in A356 alloy and the secondary dendrite spacing decreased from 41μm to 30μm. Eutectic Si microstructure from the coarse needle or strip refined to fibrous. A new AlSiYb intermetallic compound was formed in Yb-added A356 aluminum alloy. With the increase of Yb content, the mechanical properties of A356 aluminum alloy first increase and then decrease. When the Yb content is 0.2%, the mechanical properties of the alloy reaches the maximum, the tensile strength is 195 MPa and the elongation is 4.8% .