The effect of rolling reduction and annealing process on the microstructure and corrosion behavior of Mg-9Li-1Zn(LZ91) alloy was investigated. The test alloy sheets were cold rolled with the reduction of 50% and 75%, ...The effect of rolling reduction and annealing process on the microstructure and corrosion behavior of Mg-9Li-1Zn(LZ91) alloy was investigated. The test alloy sheets were cold rolled with the reduction of 50% and 75%, respectively, and then were annealed at 200 ℃ for 1 h. The microstructure of test alloys was observed by OM and SEM while the phase composition was determined by XRD. The corrosion property was evaluated by electrochemical measurements and immersion tests. The results show that LZ91 alloy sheet consists of α-Mg, β-Li and precipitated Mg-Li-Zn compounds(MgLi2Zn and MgLiZn phases). Dynamic recrystallization grains appear in β-Li phase during annealing process, leading to grain refinement. The results indicate that the increasing rolling reduction and performing the annealing process can enhance the corrosion resistance of LZ91 alloy. The 75% cold-rolled and annealed LZ91 alloy shows the best corrosion resistance.展开更多
The as-rolled AZ31 Mg alloy sheets are welded by friction stir welding（FSW） in this study, followed by annealing and hot rolling with different reductions. The effects of welding speed and the rolling reduction on t...The as-rolled AZ31 Mg alloy sheets are welded by friction stir welding（FSW） in this study, followed by annealing and hot rolling with different reductions. The effects of welding speed and the rolling reduction on the microstructure, tensile properties, microhardness and fracture surfaces of the specimens are investigated. The results show that the microstructures of the FSW joint in different regions become more and more consistent as the hot rolling reduction increases. The mechanical properties of the FSW joints and the joint coefficient are improved with increasing rolling reduction; however,the hardness value in the stirred zone decreases firstly and then increases. When the rolling reduction is 50%, the tensile strength of FSW joint is close to that of base metal. The sample L_3 achieves the best comprehensive properties, with the yield strength, ultimate tensile strength and elongation of 162, 287.9 MPa, and 17.9%, respectively.展开更多
基金Projects(2016YFB07004032016YFB0301100)supported by the National Key Research and Development Program of China+3 种基金Project(cstc2019jcyj-msxmX0306)supported by the Chongqing Research Program of Basic Research and Frontier Technology,ChinaProjects(2018CDGFCL00052018CDJDCL0019)supported by the Fundamental Research Funds for the Central Universities,ChinaProject(B16007)supported by the 111 Program of Ministry of Education and the State Administration of Foreign Experts Affairs of China。
文摘The effect of rolling reduction and annealing process on the microstructure and corrosion behavior of Mg-9Li-1Zn(LZ91) alloy was investigated. The test alloy sheets were cold rolled with the reduction of 50% and 75%, respectively, and then were annealed at 200 ℃ for 1 h. The microstructure of test alloys was observed by OM and SEM while the phase composition was determined by XRD. The corrosion property was evaluated by electrochemical measurements and immersion tests. The results show that LZ91 alloy sheet consists of α-Mg, β-Li and precipitated Mg-Li-Zn compounds(MgLi2Zn and MgLiZn phases). Dynamic recrystallization grains appear in β-Li phase during annealing process, leading to grain refinement. The results indicate that the increasing rolling reduction and performing the annealing process can enhance the corrosion resistance of LZ91 alloy. The 75% cold-rolled and annealed LZ91 alloy shows the best corrosion resistance.
基金financial support by the National Key Research and Development Program of China(Project Nos.2016YFB0301100 and 2016YFB0700403)the National Natural Science Foundation(Project No.51601024)+2 种基金the National Key Research,the Chongqing Research Program of Basic Research and Frontier Technology(Project No.cstc2016jcyj A0418)the National Natural Science Foundation of China(Grant No.51701026)the Fundamental Research Funds for the Central Universities(Project No.106112017CDJXY130001)
文摘The as-rolled AZ31 Mg alloy sheets are welded by friction stir welding（FSW） in this study, followed by annealing and hot rolling with different reductions. The effects of welding speed and the rolling reduction on the microstructure, tensile properties, microhardness and fracture surfaces of the specimens are investigated. The results show that the microstructures of the FSW joint in different regions become more and more consistent as the hot rolling reduction increases. The mechanical properties of the FSW joints and the joint coefficient are improved with increasing rolling reduction; however,the hardness value in the stirred zone decreases firstly and then increases. When the rolling reduction is 50%, the tensile strength of FSW joint is close to that of base metal. The sample L_3 achieves the best comprehensive properties, with the yield strength, ultimate tensile strength and elongation of 162, 287.9 MPa, and 17.9%, respectively.
