TC4钛合金板带高温成形性能研究

以TC4钛合金板带为研究对象，重点对其高温下的强度和热导率以及表面氧化皮等进行试验研究和分析.TC4钛合金的屈服强度和抗拉强度以及屈强比均随温度的升高而降低.所测合金的比热容范围为0.61~1.14 J/（kg·K），热辐射系数为0.58.TC4合金表面氧化缺陷层主要由外侧含氧量较高的氧化皮和内侧的富氧层组成.随加热温度的升高和保温时间的延长，富氧层会向合金基体延伸使其氧化层厚度增加.在较高的应变速率和较低的变形温度下，TC4合金的变形抗力增加明显.应力-应变曲线随应变速率的降低由加工硬化型向动态再结晶型转变，变形温度越高其发生动态再结晶的临界变形量越小.

Study on High Temperature Forming Performance of TC4 Titanium Alloy Strip

Taking TC4 alloy as the object of study,the strength and the thermal conductivity and surface oxide layer of the strip at high temperature were emphatically studied and analysised in this paper.The yield strength and tensile strength and flexor strength ratio of the TC4 alloy decreased with the increase of deformation temperature.The specific heat range was 0.61-1.14 J/(kg·K) and the thermal radiation coefficient was 0.58 of the tested TC4 alloy.The surface oxide layer of the TC4 alloy was mainly composed of oxide coating part with high oxygen content outside and oxygen-rich part inside.The thickness of oxide layer increased with the increase of heating temperature and the holding time because the part of high oxygen content extended into alloy matrix.The deformation resistance of TC4 alloy increased obviously at higher strain rate and lower deformation temperature.The stress-strain curve changed from the type of work hardening to dynamic recrystallization with the decrease of the strain rate.The higher the deformation temperature,the smaller the critical deformation of the dynamic recrystallization.