摘要
采用砂型铸造、金属型铸造和砂型低压铸造制备了Al-2Li-2Cu-0.5Mg-0.2Sc-0.2Zr合金,研究了不同铸造方法对其组织和力学性能的影响。结果表明,不同铸造方法制备合金的组织主要由α-Al相、δ′-Al_(3)Li、θ-Al_(2)Cu、T_(1)-Al_(2)CuLi等相构成。冷却速率和压力改变了析出相密度,主要为含Sc相和富Cu析出相。随着冷却速度和压力增加,其组织得到细化,金属型铸造晶粒尺寸约为34.85μm,砂型低压铸造的晶粒尺寸约为42.42μm。金属型铸造的抗拉强度为277MPa,低压铸造的伸长率可达到1.5%。通过对断口分析,发现金属型铸造和砂型低压铸造合金均含有大量的韧窝,而砂型铸造合金中韧窝含量较少,这主要与合金的晶粒尺寸、第二相尺寸与密度、内部缺陷等有关。
Al-2 Li-2 Cu-0.5 Mg-0.2 Sc-0.2 Zr alloys were prepared by sand casting,metal mold casting and low pressure casting,respectively.The microstructure and mechanical properties of the alloys with different casting methods were investigated by OM,SEM,XRD and tensile testing.The results show that the as-cast microstructure of the alloy by different casting methods mainly consists ofα-Al,δ′-Al_(3)Li,θ-Al_(2)Cu,T_(1)-Al_(2)CuLi.With a higher cooling rate and pressure,the density of precipitates mainly composed of Al3Zr and copper-rich phase are varied.With the increase of the cooling rate and pressure,the microstructure of alloy is refined,where the grain size of metal mold casting and low-pressure casting is about 34.85μm and 42.42μm,respectively.In addition,the ultimate tensile strength of alloy by metal mold casting reach up to 277 MPa,while the elongation of alloy by low pressure casting reaches 1.5%.The fracture morphology show that the alloy by metal mold casting and low-pressure sand casting contain a large number of dimples,however sand mold casting alloys have more internal defects,which are mainly related to the grain size,secondary phase size and density,internal defects of the alloy.
作者
王一笑
吴国华
张亮
张小龙
李沛森
Wang Yixiao;Wu Guohua;Zhang Liang;Zhang Xiaolong;Li Peisen(National Engineering Research of Center of Light Alloy Net Forming,School of Materials Science and Engineering,Shanghai Jiaotong University;Shanxi Jianghuai Heavy Industry Co.,Ltd.)
出处
《特种铸造及有色合金》
CAS
北大核心
2022年第9期1097-1101,共5页
Special Casting & Nonferrous Alloys
基金
国家自然科学基金资助项目(51871148,51821001)
国家重点研发计划资助项目(2016YFB0301003)
作者简介
第一作者:王一笑,男,1992年出生,博士研究生,上海(200240),E-mail:wyixiao@sjtu.edu.cn;通信作者:吴国华,男,1964年出生,教授,上海(200240),E-mail:ghwu@sjtu.edu.cn
