Sr及RE变质对砂型铸造ZL114A合金组织及力学性能的影响  

Effects of Sr and RE Modifier on Microstructure and Mechanical Properties of ZL114A Alloy in Sand Casting

作　　者：蒋清[1] 孟祥炜[1] 肖文丰[1] 崇贤博 马芳[1] 

机构地区：[1]首都航天机械公司,北京100076

出　　处：《热加工工艺》2015年第15期35-37,41,共4页Hot Working Technology

摘　　要：采用20和40 mm厚的ZL114A两种试样,对比研究了稀土变质和锶变质对砂型铸造ZL114A合金试样力学性能和组织的影响。结果表明:不变质、稀土变质和锶变质等三种方案的试样抗拉强度差异较小(在5%以内),而伸长率差异较大。锶变质后的试样(T6状态)伸长率最高,比其它两种方案高出28%以上。通过对比三种方案伸长率最小的试样组织发现,锶变质试样的共晶硅组织细化最明显,且试样聚集性的孔洞类缺陷又较少,这对试样的伸长率提升有很大作用。稀土变质后的试样组织中会形成一些树枝状或片层状化合物Al REMg Si相,且聚集性的孔洞类缺陷较多,这类组织反而降低了试样的伸长率。The effects of Sr and RE modifier on the microstructure and mechanical properties of ZL114 A alloy in sand-casting were investigated using the two different thickness samples including 20 mm and 40 mm. The results show that the tensile strength difference of three different samples including unmodified sample, RE-modified sample and Sr-modified sample, is less than 5 %, but the elongation of these three different samples is much more different. The elongation of Sr-modified sample is 28 % more than the other samples. The microstructure of the least elongation sample in each scheme was comparatively investigated, it was shown that the shape of the eutectic silicon after modified by Sr is fine particulate, and is few congregate hole-disfigurement. The microstructure is helpful to improve the elongation of the sample. After it is modified by mixed RE, the microstructure of the sample has some dendritic or sheet Al REMg Si compound, which is much more congregate hole-disfigurement, however, the microstructure can reduce the elongation of the sample.

关 键 词：砂型铸造 ZL114A 锶变质 伸长率 

分 类 号：TG245[金属学及工艺—铸造] TG292