偏析缺陷等级对WE43A镁合金力学性能及耐蚀性能的影响  

Effect of Segregation Defect Grade on Mechanical Properties and Corrosion Resistance of WE43A Magnesium Alloy

作　　者：王子峰 魏振伟 邹爱华[1] 李志鹏[1] 赵伟 杨光山 刘昌奎 WANG Zifeng;WEI Zhenwei;ZOU Aihua;LI Zhipeng;ZHAO Wei;YANG Guangshan;LIU Changkui(School of Materials Science and Engineering,Nanchang Hangkong University,Nanchang 330063,Jiangxi,China;Aviation Industry Failure Analysis Center,Beijing 100095,China;Beijing Key Laboratory of Aeronautical Materials Testing and Evaluation,Beijing 100095,China;Key Laboratory of Aeronautical Science and Technology for Material Testing and Evaluation,Beijing 100095,China;Key Laboratory of Material Testing and Evaluation,Aero Engine Corporation of China,Beijing 100095,China;AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China;Avic Harbin Dongan Engine Co.,Ltd.,Harbin 150066,Heilongjiang,China)

机构地区：[1]南昌航空大学材料科学与工程学院,江西南昌330063 [2]航空工业失效分析中心,北京100095 [3]航空材料检测与评价北京市重点实验室,北京100095 [4]材料检测与评价航空科技重点实验室,北京100095 [5]中国航空发动机集团材料检测与评价重点实验室,北京100095 [6]中国航发北京航空材料研究院,北京100095 [7]中国航发哈尔滨东安发动机有限公司,黑龙江哈尔滨150066

出　　处：《热处理技术与装备》2024年第4期31-38,共8页Heat Treatment Technology and Equipment

基　　金：江西省重点研发计划(CK201901361);中国航发集团创新基金(ZZCX-2019-023)。

摘　　要：通过金相显微镜和扫描电子显微镜观察、室温拉伸测试、四点弯曲疲劳测试及电化学测试等方法,研究了不同偏析等级对WE43A镁合金力学性能及耐腐蚀性能的影响。结果表明,偏析组织主要以连续网格状Mg_(41)Nd_(5)相和较小颗粒状Mg_(24)Y_(5)相组成,且偏析主要分布在晶界位置。当偏析等级不大于PX4级时,WE43A镁合金的抗拉强度和塑性指标小幅度下降;当偏析等级大于PX4级时,其抗拉强度和塑性指标开始显著下降,抗拉强度、延伸率、断面收缩率分别最大下降约48%、81%、89%。偏析缺陷对WE43A镁合金的屈服强度和弹性模量影响不明显。疲劳寿命(lg)和疲劳极限最大下降比例约为33%和39%。随着偏析缺陷等级的增加,WE43A镁合金腐蚀电位从-1.573 V正移至-1.432 V,腐蚀电流密度从2.090×10^(-5)A/cm^(2)增加至2.467×10^(-3)A/cm^(2),其数量级跨度为2。WE43A镁合金在3.5ω%NaCl溶液中的腐蚀产物主要为MgO和MgCl_(2)。The effects of different segregation grades on the mechanical properties and corrosion resistance of WE43A magnesium alloy were studied by means of metallographic microscope and scanning electron microscope observation,tensile test at room temperature,four-point bending fatigue test and electrochemical test.The results show that the segregation structure is mainly composed of continuous mesh Mg_(41)Nd_(5)phase and smaller granular Mg_(24)Y_(5)phase,and the segregation is mainly distributed at the grain boundary.When the segregation grade is less than PX4,the tensile strength and plasticity indexes of the WE43A magnesium alloy only decrease slightly.When the segregation grade is more than PX4,the tensile strength and plasticity indexes begin to decrease significantly,and the tensile strength,elongation and section shrinkage decrease by about 48%,81%,89%,respectively.The effect of segregation defects on the yield strength and elastic modulus of WE43A magnesium alloys is not obvious.The maximum reduction in fatigue life(lg)and fatigue limit is approximately 33%and 39%.With the increase of segregation grade,the corrosion potential of WE43A magnesium alloy is moving from-1.573 V to-1.432 V,and the corrosion current density increases from 2.090×10^(-5)A/cm^(2)to 2.467×10^(-3)A/cm^(2),with an order of magnitude span of 2.The corrosion products of WE43A magnesium alloy in 3.5ω%NaCl solution are mainly MgO and MgCl_(2).

关 键 词：偏析缺陷 WE43A镁合金 断口特征 耐腐蚀性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程]