7075铝合金棒材探伤不合格的原因分析及预防措施

The Disqualification Reason and Preventive Measures for 7075 Aluminum Alloy Bar

通过显微组织、扫描电镜观察及能谱分析等手段,分析了7075铝合金棒材探伤不合格的产生原因,结果表明:铸锭中存在粗大金属化合物聚集,挤压变形时由于粗大的金属间化合物破碎产生微裂纹破坏了金属的连续性,导致探伤不合格。能谱分析结果确认粗大化合物为Al-Cr相,并从形成机理上对粗大金属化合物的成因进行了分析,从合金元素含量、熔铸温度、中间合金的使用等方面提出了解决措施。

Through the microstructure, scanning electron microscopy （sem）, energy spectrum analysis and other means, this paper analyzes the unqualified reason of inspection for 7075 aluminum alloy bar. The results show that the billet exists bulky compound aggregation. During the extrusion deformation, it produce micro crack which destroy the continuity of metal and lead to the unqualified inspection ,due to that coarse intermetallic compound is broken. Spectrum analysis results confirm that the bulky compound is AI - Cr phase. It analyzes the cause of large metal compounds from the formation mechanism and put forwards useful measures from the content of alloy elements, casting temperature, and use of intermediate alloy.