摘要
ZTA15钛合金铸件在进行精密加工过程中存在局部掉块现象。利用多种微观物理表征分析手段,即OM、SEM、EDS、XRD,结合拉伸性能结果,分析对比掉块区域和正常区域的显微组织与力学性能,探讨掉块区域异常组织对拉伸行为的影响机制。结果表明:掉块区域与正常区域虽均呈双态组织,但掉块区域组织中β相含量远超过正常区域,出现了β斑。微区成分分析表明Fe元素的偏析是导致异常组织和β斑的最主要因素,同时也是导致合金的塑性急剧下降的主要原因。Fe元素的偏析改变了合金的组织结构,这主要是因为Fe在α-Ti中的饱和度仅有0.1%(质量分数),从而导致脆性TiFe共晶相的形成,提高强度却降低了合金铸件的塑性,导致铸件在加工过程中掉块。
Partial block-dropping phenomenon was existed during the precision process of TA15 titanium alloy casting. In view of multiple means of microscopic physical characterization analysis such as OM/SEM/EDS/XRD and by considering the tensile performance results, the microstructure and mechanical properties between block-dropping area and the regular areahad been investigated. This article focused on the impact mechanism on tensile behavior that generated from the abnormal structure of blockdropping area. The results reveal that both the block-dropping area and the regular area show bi-modal microstructure, whereas the βphase concentration of the block-dropping area is far beyond the regular area and emerges as β spot. Microanalysis shows that the segregation of Fe is the major factor causing the abnormal structure and β spot, as well as the sharp plasticity decreases of alloy. The segregated Fe alters the microstructure and properties of the alloy, mainly because the saturation of Fe in α-Ti is only 0.1%, which leads to the formation of brittle TiFe eutectic phase. The increase of strength reduces the plasticity of the alloy casting, and further lead to the block-dropping during the process.
作者
刘高扬
赵文侠
王曦
LIU Gaoyang;ZHAO Wenxia;WANG Xi(AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China)
出处
《航空材料学报》
EI
CAS
CSCD
北大核心
2020年第4期45-51,共7页
Journal of Aeronautical Materials
关键词
钛合金铸件
β斑
拉伸性能
TiFe共晶相
沿晶断裂
titanium alloy casting
βspot
tensile performance
TiFe eutectic phase
intergranular fracture
作者简介
通讯作者:刘高扬(1983-),男,硕士,工程师,主要从事失效分析与预防相关工作,联系地址:北京市海淀区温泉镇环山村航材院(100095),E-mail:liugaoyang816@163.com。
