摘要
研究了不同温度等温压缩变形及热处理后对损伤容限型钛合金TC4-DT断裂韧性的影响,对比分析了各个温度下的显微组织与断裂韧性的关系,用扫描电镜对断口进行了观察。研究结果表明,两相区较低温度等温压缩变形得到等轴组织,较高温度得到双态组织;相变点以上得到片层组织,片状组织的断裂韧性高于等轴组织。4种温度的断口均为等轴韧窝型延性断裂,随着温度的升高,断面粗糙度增加,韧窝直径和深度逐渐下降,在片层组织中发现了二次裂纹。
The influences of isothermal deformation at different temperature on fracture toughness of damage tolerance titanium alloy TC4-DT were studied.The microstructure and fracture toughness were compared and analyzed.The fracture surface was investigated by SEM.The results show that,when deformation is in the lower region of the two phase,equiaxial α phase can be obtained,while in the higher region,bi-modal microstructure can be acquired.The fracture toughness of lamellar microstructure is higher than that of equiaxial microstructure when deformed above the phase transition.The fracture at every temperature is equiaxed dimple-type ductile fracture.With the increase of temperature,the roughness of fracture surfaces increases and the diameter and depth of dimple decrease.Secondary cracks are observed in the lamellar microstructure.
出处
《热加工工艺》
CSCD
北大核心
2011年第20期64-67,共4页
Hot Working Technology
