循环热处理对喷射沉积Al-27%Si合金组织和性能的影响  

Effects of thermal cycling process on microstructure and properties of spray-formed Al-27%Si alloy

作　　者：朱学卫[1] 王日初[1] 彭健[1] 彭超群[1] 刘文水[1] 

机构地区：[1]中南大学材料科学与工程学院,湖南长沙410083

出　　处：《材料热处理学报》2015年第6期58-64,共7页Transactions of Materials and Heat Treatment

基　　金：国家军品配套项目(JPPT-125-GH-039)

摘　　要：采用喷射沉积技术制备Al-27%Si(质量分数)合金,研究循环热处理对其组织、残余应力和力学性能的影响。采用Ansys有限元模拟结合X射线检测评估Al-27%Si合金残余热应力的分布和大小。结果表明,喷射沉积Al-27%Si合金由均匀细小的初晶Si和α-Al基体组成,初晶Si的尺寸随热循环温度升高和次数增加而增大。Ansys有限元模拟结果显示喷射沉积Al-27%Si合金增强体Si颗粒受径向拉应力,Al基体受径向压应力,平均残余热应力为121 MPa,小于X射线法测的平均残余应力131.7 MPa。Al-27%Si合金屈服强度与残余热应力、Si相形貌和大小有关。循环热处理后,当Si相形貌和尺寸相当时,材料的屈服强度随残余热应力的降低而升高;当Si相尺寸随热循环增大时,在残余应力相当的情况下材料的屈服强度降低。The Al-27% Si( mass fraction) alloy was prepared by the spray-formed process. The effects of thermal cycling on microstructure,mechanical properties and residue stress of the alloy were investigated. The distribution and value of residue thermal stress in Al-27% Si alloy were evaluated by Ansys finite element simulation with the X-ray detection. The results show that the spray-formed Al-27% Si alloy is composed of fine,uniform primary Si phase and α-Al matrix. The primary Si phase grows with increasing thermal cycling temperature and times. The Ansys simulation result shows that,the Si particles in spray-formed Al-27% Si alloy suffer a strain stress,where the α-Al matrix suffers a compress stress on the radial direction. The mean residue thermal stress is 121 MPa in Al-27% Si alloy,which is smaller than that of obtained by X-ray detection method of 131. 7 MPa. The yield strength of the Al-27% Si alloy is relative to the residue thermal stress,size and morphology of Si phase. After thermal cycling process,the yield strength increases with the decreasing of residue thermal stress when the size and morphology of Si phase are invariant. However,when size of Si phase growth in thermal cycling process,the yield strength of the Al-27% Si alloy decreases accordingly.

关 键 词：喷射沉积 Al-27%Si合金 循环热处理 ANSYS模拟 残余应力 

分 类 号：TG166.3[金属学及工艺—热处理]