Sc添加量对Al-Si系活塞合金组织及蠕变性能的影响  

Effects of Sc Content on Microstructure and Creep Properties of Al-Si Series Piston Alloy

作　　者：雷欣 郭永春[1] 王建利[1] 李建平[1] LEI Xin;GUO Yongchun;WANG Jianli;LI Jianping(School of Material and Chemical Engineering,Xi'an Technological University,Xi'an 710021,China)

机构地区：[1]西安工业大学材料与化工学院,陕西西安710021

出　　处：《热加工工艺》2023年第22期89-94,共6页Hot Working Technology

基　　金：西安市智能兵器重点实验室项目(2019220514SYS020CG042);陕西省重点研发计划项目(2020ZDLGY13-01,2018ZDCXLGY-09-08)。

摘　　要：对复杂Al-Si系活塞铝合金中添加不同含量的Sc(0wt%、0.2wt%、0.4wt%和0.6wt%)所引起的合金组织及蠕变性能的影响进行了研究。结果表明:当基体合金中加入Sc元素时,有一种块状的ScSiNi相形成,它以两种形式存在,一种与初生Si紧密结合存在于初生Si周围,而另一种在基体中单独析出。添加Sc元素后,活塞合金中α-Al相及初生Si相的尺寸明显细化,δ-Al3CuNi相发生团簇鱼骨状→杆棒状→团簇鱼骨状的转变。当Sc元素添加量为0.2wt%时,该合金在350℃高温、25 MPa应力下的稳态蠕变速率明显下降,此时位错运动占主导因素;加入0.6wt%Sc元素,晶界滑动占据了主要原因,该合金的抗稳定蠕变性能下降。The effects of adding different content of Sc(0wt%,0.2wt%,0.4wt%and 0.6wt%)on the microstructure and creep properties of complex Al-Si piston aluminum alloy were investigated.The results show that Sc element forms in piston aluminum alloy to form a blocky Sc-rich phase identified as ScSiNi phase,which has two existence forms,one existing independently in the matrix and another being tightly bound to the primary Si.The size ofα-Al and primary Si in the cast alloy added with different content of Sc reduces by different degrees,at the same time,theδ-Al3CuNi phase shape occurs by Cluster fish bone-like to bar rod shape to cluster fish bone-like.The alloy with 0.2wt%Sc,the steady-state creep rate is substantially reduced under 350℃and 25 MPa stress,when the dislocation motion is the dominant factor.After adding 0.6wt%Sc to the alloy,crystal boundary sliding is the dominant factor,and the creep resistance of the alloy reduces.

关 键 词：Al-Si-Cu-Ni-Mg活塞合金 SC 抗蠕变性能 

分 类 号：TG111.8[金属学及工艺—物理冶金] TG146.21[金属学及工艺—金属学]