摘要
为了确定挤压态Mg-5Sn-2Si-2Sr合金合适的热处理方案,分别采用硬度计、X射线衍射仪、力学性能试验机、光学显微镜,研究了该合金经T4(固溶处理)、T5(200℃×12 h时效)和T6(固溶+时效)热处理后显微组织及力学性能的变化。结果表明:挤压态Mg-5Sn-2Si-2Sr合金宜采用T5热处理工艺。经T5热处理后,在晶界处析出大量Mg2Si强化相,使合金的屈服强度、抗拉强度分别达210.9 MPa、257.0 MPa,高于挤压态、T4和T6热处理工艺下的合金强度。T4热处理时,固溶强化作用远小于退火软化作用,致使合金力学性能的下降。T6热处理时,析出相及晶粒尺寸的长大使得合金力学性能的提高受到了限制。
In order to give a suitable heat treatment process for an as-extruded M g-5Sn-2Si-2Sr alloy, the microstructure and mechanical properties of the as-extruded alloy after T4 （solid solution） , T5 （200℃× 12 h aging） , T6 （solid solution ＋ aging） heat treatment were investigated by means of hardness test, X-ray diffraction, tensile test and optical microscopy. The results show that T5 treatment is appropriate for the as-extruded Mg-SSn-2Si-2Sr alloy and large amount of Mg2 Si precipitated phases are observed on the grain boundaries. The yield and tensile strengths of the alloy treated by T5 process are 210. 9 MPa and 257.0 MPa, respectively, which is higher than that of the alloy treated by other processes. The mechanical property is decreased after T4 treatment because the effect of softening annealing is much stronger than solid solution strengthening. The mechanical properties can not be improved after T6 treatment due to the increase of the second phase size and the grain growth.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2013年第10期78-82,共5页
Transactions of Materials and Heat Treatment
基金
沈阳市科技计划项目(F12-277-1-34
F12-277-1-35)
