成形工艺对铝锶合金组织性能及细化性能的影响  

Microstructure,Properties and Refining Performance of Al-Si Alloy under Different Forming Process

作　　者：万帆 运新兵[1] 毕胜[1] 裴久杨[1] 杨军[2] 闫志勇 Wan Fan;Yun Xinbing;Bi Sheng;Pei Jiuyang;Yang Jun;Yan Zhiyong(Engineering Research Center of Continuous Extrusion, Dalian Jiaotong University, Dalian 116028, China;School of Materials Science and Engineering, Dalian Jiaotong University, Dalian 116028, China;Dalian Konform Technical Company Ltd., Dalian 116050, China)

机构地区：[1]大连交通大学连续挤压工程研究中心,辽宁大连116028 [2]大连交通大学材料科学与工程学院,辽宁大连116028 [3]大连康丰科技有限公司,辽宁大连116050

出　　处：《稀有金属》2018年第8期799-806,共8页Chinese Journal of Rare Metals

基　　金：辽宁省高等学校优秀人才支持计划项目(LR2015011)资助

摘　　要：介绍了铝锶合金线材的成形工艺，对比研究了在连铸连挤工艺、半连续铸造-卧式挤压工艺和二次连续挤压工艺下铝锶合金产品的显微组织、力学性能及其在铝硅合金铸造时的细化作用。结果表明：与卧式挤压合金相比，连铸连挤合金的抗拉强度由90MPa提高到118MPa，延伸率由10．4％下降到9．6％，Al4Sr相尺寸由60μm减小到48μm，细化性能提高。二次连续挤压合金与连铸连挤合金相比，抗拉强度由118MPa增加到133MPa，延伸率由9．6％下降到7．0％，A14Sr相尺寸由48μm减小到28μm，细化性能并没有提高。在孔隙度方面，卧式挤压合金的孔隙度最大，为2％，二次连续挤压合金的孔隙度最小，为0．25％，连铸连挤合金的孔隙度为1．09％，连续挤压成形可提高铝锶合金的致密度；并且经过二次连续挤压后，铝锶合金中基体／第二相界面结合变得牢固，内部缺陷减少，孔隙度进一步降低。铝硅合金经3种铝锶合金细化后，共晶硅形貌没有明显差别，均为细的纤维状，但α-Al相差别较大。Current forming processes of AlSi alloy were summarized and introduced. The microstructure, mechanical properties and refinement during AlSi alloy casting of the alloy produced by continuous casting and extrusion, semi-continuous casting and horizontal extrusion and secondary continuous extrusion were compared and analyzed. Results showed that compared with Al-Si alloy by horizontal extrusion, tensile strength of Al-Si alloy by continuous casting and extrusion increased from 90 to 118 MPa, its elongation decreased from 10.4% to 9.6% , and A14Sr phase in the alloy decreased from 60 to 48 μm in size. Furthermore, its refining performance improved. Tensile strength of Al-Si alloy by secondary continuous extrusion increased from 118 to 133 MPa in contrast to Al-Si alloy by continuous casting and extrusion, and its elongation reduced from 9.6% to 7.0%. Al4Sr phase in the alloy by secondary continuous extrusion deceased from 48 to 28 μm in size. Unfortunately, its refining performance did not improve. In terms of porosity, the porosity of Al-Si alloy produced by horizontal extrusion was the largest, which was 2% ; the porosity of Al-Si alloy produced by secondary continuous extrusion was least, which was 0.25% ; the porosity of Al-Si alloy produced by continuous casting and extrusion was 1.09% ; as a result, continuous extrusion forming could improve the density of Al-Si alloy, after secondary continuous extrusion, the bonding of the matrix/second phase interface of Al-Si alloy was stronger, the internal defects were reduced, and the porosity was further reduced. After refining by the three Al-Si alloys, eutectic silicon phase in Al-Si alloy did not change obviously in morphology, which was in a thin fiber shape but α-Al phase had a large difference.

关 键 词：铝锶合金 成形工艺 组织性能 晶粒细化剂 细化性能 

分 类 号：TG376[金属学及工艺—金属压力加工] TG146.21[一般工业技术—材料科学与工程]