摘要
通过高周疲劳试验研究了裂纹源位置对6005A-T6铝合金挤压型材高周疲劳寿命的影响。结果表明:6005A-T6铝合金挤压型材在应力比0.1下的中值疲劳强度为164.5 MPa,疲劳强度较高,但疲劳寿命分布较分散;在最大应力200 MPa条件下,具有不同疲劳寿命试样的疲劳裂纹源区的面积较小,疲劳裂纹扩展区均由疲劳条带和二次裂纹组成,瞬断区的面积较大,均由孔洞和韧窝组成;在相同最大应力下疲劳寿命存在差异的原因在于疲劳裂纹源位置的不同,在最大应力为200 MPa条件下,疲劳裂纹源位于孔洞缺陷处试样的疲劳寿命最长,比疲劳裂纹源位于氧化夹杂物处试样的疲劳寿命延长一个数量级,疲劳裂纹源位于Al7(Cr Fe)第二相颗粒处试样的疲劳寿命居于二者之间。
The effect of crack source location on high cycle fatigue life of 6005 A-T6 aluminum alloy extruded profiles was studied by high cycle fatigue tests.The results show that the median fatigue strength of 6005 A-T6 aluminum alloy extruded profiles was 164.5 MPa at the stress ratio of 0.1;the fatigue strength was relatively high,but the fatigue life distribution was relatively dispersal.Under the maximum stress of 200 MPa,the fatigue crack source region of samples with different fatigue lives was small;the fatigue crack propagation region consisted of fatigue strips and secondary cracks;the area of transient fracture region was large,and the region consisted of holes and dimples.The main reason for the difference in fatigue life under the same maximum stress was the difference location of fatigue crack source.Under the maximum stress of 200 MPa,the fatigue life of the sample with fatigue crack source in holes was the longest,which was one order of magnitude larger than that with fatigue crack source on oxide inclusions,and the fatigue life of the sample with the fatigue crack source in Al7(Cr Fe)second phase particles was between the two.
作者
张岚
赵鸿金(指导)
李声慈
叶青
李德华
ZHANG Lan;ZHAO Hongjin;LI Shengci;YE Qing;LI Dehua(School of Materials Science and Engineering,Jiangxi University of Science and Technology,Ganzhou 341000,China;Guangdong Jianmei Aluminum Profile Factory Co.Ltd.,Shunde 528300,China)
出处
《机械工程材料》
CAS
CSCD
北大核心
2020年第1期16-20,28,共6页
Materials For Mechanical Engineering
基金
国家自然科学基金资助项目(51475040)
江西省教育厅科学技术研究项目(GJJ170551)
江西理工大学研究生创新专项项目(ZS2018-S083).
关键词
铝合金
高周疲劳寿命
裂纹源
孔洞
氧化夹杂物
第二相颗粒
aluminum alloy
high cycle fatigue life
crack source
hole
oxide inclusion
second phase particle
