2024-T3铝合金单搭接化铣板疲劳特性及失效机理  

Fatigue Properties and Failure Mechanisms of Single-lap Chemical Milling on 2024-T3 Aluminum Alloy Sheet

作　　者：杨廷勇 邓文[1] 李建伟 朱志鹏 YANG Ting-yong;DENG Wen;LI Jian-wei;ZHU Zhi-peng(China Helicopter Research and Development Institute,Jiangxi Jingdezhen 333001,China;Aviation Military Representative Office of the Aviation Military Representative Bureau of the Army Equipment Department in Jingdezhen,Jiangxi Jingdezhen 333002,China)

机构地区：[1]中国直升机设计研究所,江西景德镇333001 [2]陆军装备部航空军事代表局驻景德镇地区航空军事代表室,江西景德镇333002

出　　处：《装备环境工程》2022年第10期65-72,共8页Equipment Environmental Engineering

摘　　要：目的 研究2024-T3铝合金单搭接化铣板的疲劳性能及失效形式。方法 采用步进法对化铣板搭接件进行疲劳试验,运用奈尔检验法对疲劳强度进行数据处理,运用扫描电子显微镜和能谱分析对典型疲劳断口进行观察和成分分析,对比基板厚度和铆钉孔径对化铣板搭接件疲劳强度的影响,分析并探讨2024-T3铝合金化铣板搭接件的疲劳失效形式及机理。结果 基板厚度对2024-T3铝合金化铣板搭接件的疲劳强度影响较大,而铆钉孔径影响较小。随着基板厚度的增加,化铣板搭接件的疲劳强度呈现出降低的趋势,对2种铆钉孔径(3、4 mm),厚度为1.8 mm化铣板搭接件的疲劳强度较厚度为0.6 mm的试样分别降低了13.2%和13.0%。基板厚度增加使铝合金化铣板搭接件的疲劳失效形式从上基板铆钉头部失效变为下基板纽扣处失效,并最终表现为铆钉断裂失效。结论 随着基板厚度增加,搭接件微动磨损加剧,加速了疲劳裂纹萌生,这是造成2024-T3铝合金化铣板搭接件疲劳强度显著降低的主要原因。This paper aims to study the fatigue properties and failure mode of 2024-T3 aluminum alloy single-lap chemical milling sheet. We carried out the fatigue test on chemical milling sheet joint with different sizes by using the step-by-step method, processed the fatigue strength data by using the Nair test method, observed the typical fatigue fracture, and analyzed by using the scanning electron microscope and Energy spectrum analysis. We compared the effects of substrate thickness and rivet aperture on the fatigue strength of aluminum alloy chemical milling sheet joint as well as analyzed and discussed the fatigue failure mode and mechanism of 2024-T3 aluminum alloy single-lap chemical milling sheet joint. The result shows that the substrate thickness has a great influence on the fatigue strength of 2024-T3 aluminum alloy chemical milling sheet jointwhile the rivet aperture has little influence.With the increase of substrate thickness, the fatigue strength of aluminum alloy chemical milling sheet joint shows a gradual decreasing trend. For two kinds of rivet holes(3 mm and 4 mm), the fatigue strength of chemical milling sheet joint with thickness of 1.8 mm is 13.2% and 13.0% lower than that of 0.6 mm respectively. With the increase of substrate thickness, the fatigue failure mode of aluminum alloy milling sheet joint changes from rivet head failure of upper substrate to button failure of lower substrate and rivet fracture failure in the end. In addition, the fretting wear of the lap joint is intensified and fatigue crack initiation is accelerated, which is the main reason for the significant reduction of fatigue strength of 2024-T3 aluminum alloy milling sheet joint.

关 键 词：2024-T3铝合金 化铣板 单搭接 疲劳试验 微动磨损 步进法 

分 类 号：TG146.21[一般工业技术—材料科学与工程]