摘要
本文研究了超声处理和挤压力大小对流变挤压铸造过共晶Al-Si合金富铁相和力学性能的影响。结果表明,当施加挤压力为0时,无超声液态挤压铸造Al-17Si-1Fe合金铸态组织中富铁相主要为长针状β相,Al-17Si-2Fe合金铸态组织中富铁相除了针状β相外,还有板条状的δ相;随着挤压力的增大,富铁相尺寸逐渐减小。超声处理后,Al-17Si-1Fe合金组织中出现了块状δ相,且压力下凝固使得富铁相进一步得到细化。对于同种成分的合金而言,相同挤压力作用下,有超声处理合金试样的抗拉强度和伸长率大于无超声处理的合金试样,且合金抗拉强度和伸长率均随着挤压力的增大而增大。未经超声处理时,当挤压力在0~300 MPa范围,Al-17Si-1Fe合金抗拉强度比Al-17Si-2Fe合金高出约16.3%~19.0%;而经过超声处理后,相同挤压力作用下,Al-17Si-2Fe合金的抗拉强度仅略低于Al-17Si-1Fe合金。
The effects of ultrasonic treatment and pressure on the iron-rich phase and mechanical properties of rheo-squeeze cast hypereutectic Al-Si alloys were investigated.The results show that the iron-rich phase in the as-cast microstructure of Al-17Si-1Fe alloy without ultrasonic treatment is mainly the long needle-likeβphase when the applied pressure is 0.Apart from the needle-likeβphase,the iron-rich phase in the as-cast microstructure of Al-17Si-2Fe alloy also contains plate-likeδphase.With the increase of pressure,the size of the iron-rich phase decreases gradually.After ultrasonic treatment,the block-likeδphase appears in the as-cast microstructure of Al-17Si-1Fe alloy,and the following solidification under pressure further refines the iron-rich phase.For alloys with the same composition,under the same pressure,the tensile strength and elongation rate of the alloy sample with ultrasonic treatment are greater than that of the alloy sample without ultrasonic treatment,and the tensile strength and elongation rate increase with the increase of the pressure.Without ultrasonic treatment,when the pressure is in the range of 0~300 MPa,the corresponding tensile strength of Al-17Si-1Fe alloy is about 16.3%~19.0%higher than that of Al-17Si-2Fe alloy.After ultrasonic treatment,the tensile strength of Al-17Si-2Fe alloy is only slightly lower than that of Al-17Si-1Fe alloy under the same pressure.
作者
林冲
朱文波
何毅斌
Lin Chong;Zhu Wenbo;He Yibin(School of Mechanical and Electrical Engineering, Wuhan Institute of Technology, Wuhan 430205, China)
出处
《武汉科技大学学报》
CAS
北大核心
2020年第6期406-412,共7页
Journal of Wuhan University of Science and Technology
基金
国家自然科学基金资助项目(51605342).
关键词
过共晶AL-SI合金
流变挤压铸造
挤压力
超声处理
显微组织
力学性能
hypereutectic Al-Si alloy
rheo-squeeze casting
extrusion force
ultrasonic treatment
microstructure
mechanical property
