CAJ | 학술논문

利用INSTRON准静态试验机和分离式Hopkinson压杆系统对铸造镁合金AZ91在不同应变率下进行压缩试验,研究AZ91镁合金在高应变率范围内(应变率6×102～1×104 s-1)的动态力学行为,并利用扫描电镜观察试样在不同应变率下破坏断口微观形貌的变化,探索应变率对破坏机理的影响.结果表明:室温下铸造镁合金AZ91具有明显的应变硬化性质;在准静态压缩过程中材料对应变率负敏感,当应变率达到7×103 s-1时,AZ91镁合金表现出明显的应变率敏感性;在准静态破坏和动态破坏下,材料断口的微观形貌具有很大不同.
이용INSTRON준정태시험궤화분리식Hopkinson압간계통대주조미합금AZ91재불동응변솔하진행압축시험,연구AZ91미합금재고응변솔범위내(응변솔6×102～1×104 s-1)적동태역학행위,병이용소묘전경관찰시양재불동응변솔하파배단구미관형모적변화,탐색응변솔대파배궤리적영향.결과표명:실온하주조미합금AZ91구유명현적응변경화성질;재준정태압축과정중재료대응변솔부민감,당응변솔체도7×103 s-1시,AZ91미합금표현출명현적응변솔민감성;재준정태파배화동태파배하,재료단구적미관형모구유흔대불동.
The mechanical behavior of cast AZ91 under a wide range of strain rates (10-3-104 s-1) was described by using INSTRON testing system and Split Hopkinson Pressure Bar. The dynamic behavior (strain rate 6×102-1×104 s-1) of AZ91 was studied. The fracture surface of samples at different strain rates was examined by scanning electron microscope (SEM). The results show that the cast AZ91 has obvious strain hardening character at room temperature. The mechanical behavior of cast AZ91 declines as the strain rate increases under a low strain rate range (10-3-10-1 s-1). When the strain rate exceeds 7×103 s-1, the cast AZ91 shows strong strain rate sensitivity. And the microstructure of the sample's fracture surface exits great difference under different strain rates.