摘要
目的优化晶粒细化剂Al-5Ti-1B的加入速度,以改善8079铝合金铸轧板坯质量。方法用电解铝液配料直接铸轧生产8079铝合金铸轧板坯,采用光学显微镜(OM)、扫描电子显微镜(SEM)和电子万能力学实验机等手段,研究了在晶粒细化剂Al-5Ti-1B加入速度(175、185、195、205 mm/min)不同时铝合金铸轧板坯显微组织和力学性能的变化规律,并对其影响机理进行了探讨。结果随着晶粒细化剂Al-5Ti-1B加入速度的增大,铸轧板坯晶粒尺寸先急剧减小后趋于平缓,其抗拉强度和断后伸长率先增大后减小。当加入速度为175 mm/min时,铸轧板坯晶粒尺寸约为110μm,其抗拉强度和断后伸长率分别为113.0 MPa和22%;当加入速度为185~195 mm/min时,铸轧板坯晶粒细小、分布均匀,尺寸为57~59μm,其抗拉强度不低于134.3MPa,断后伸长率不低于36.0%;当加入速度为205 mm/min时,铸轧板坯晶粒尺寸变化不大,尺寸约为56μm,但在基体组织中开始出现偏析聚集现象,力学性能急剧下降,抗拉强度仅为89.7 MPa,断后伸长率仅为16.7%。能谱检测结果表明,铸轧板坯夹杂缺陷主要由Ti、Al、O、Fe和Si等元素组成,夹杂缺陷的存在破坏了基体组织的连续性。结论当晶粒细化剂Al-5Ti-1B的加入速度为185~195 mm/min时,8079铝合金铸轧板坯具有更优的显微组织和力学性能。
The work aims to optimize the addition rate of grain refiner Al-5Ti-1B to improve the quality of 8079 aluminum alloy cast-rolling plate blank.The 8079 aluminum alloy cast-rolling plate blank was produced by direct casting and rolling with electrolytic aluminum solution.Effects of different addition rates(175,185,195,205 mm/min)of grain refiner Al-5Ti-1B wire on the microstructure and mechanical properties of aluminum alloy cast-rolling plate blank were studied with an optical microscope(OM),a scanning electron microscope(SEM)and an electronic universal mechanical testing machine.The influencing mechanism was discussed.The results showed that with the increase of the addition rate of grain refiner Al-5Ti-1B wire,the grain size of cast-rolling plate blank decreased sharply and then tended to be flat,and its tensile strength and elongation after fracture increased first,and then decreased.When the addition speed was 175 mm/min,the grain size of cast-rolling plate blank was about 110μm,its tensile strength and elongation after fracturewere 113.0 MPa and 22%respectively.When the addition speed was 185-195 mm/min,the grain size of cast-rolling plate blank was about 57-59μm with uniform distribution,its tensile strength was not less than 134.3 MPa,and its elongation after fracture was not less than 36.0%.When the addition speed was 205 mm/min,the grain size of cast-rolling plate blank had little change,which was about 56μm.However,segregation and ag-gregation began to appear in the matrix structure,and its mechanical properties decreased significantly.The tensile strength was only 89.7 MPa,and the elongation after fracture was only 16.7%.The energy spectrum test showed that the inclusion defects in the cast-rolling plate blank were mainly composed of Ti,Al,O,Fe,Si and other elements,the inclusion defect destroyed the continuity of the matrix structure.When the addition rate of grain refiner Al-5Ti-1B wire is 185-195 mm/min,the aluminum alloy cast-rolling plate blank has better microstructure and mechanical properties.
作者
刘明岗
LIU Ming-gang(School of Intelligent Engineering,Henan Mechanical and Electrical Vocational College,Zhengzhou 451191,China)
出处
《精密成形工程》
北大核心
2023年第8期81-88,共8页
Journal of Netshape Forming Engineering
基金
河南省高等学校重点科研资助项目(22B430022)。
