Ti-55531合金片层组织的表层渗硼改性研究

Study on Surface Boronizing Modification of Ti-55531 Alloy with Lamellar Microstructure

系统研究了不同温度渗硼处理对Ti-55531片层合金表层组织、成分、硬度分布及残余应力的影响。结果表明:Ti-55531合金渗硼后渗层由等轴化趋势明显的白亮产物外表层、须状组织过渡层和原始片层基体三部分组成,渗层B元素含量由表及里逐渐降低。合金表层因渗硼后形成了钛硼化合物梯度层,显微硬度得到显著提高,且从表层到心部硬度也逐渐降低。另外,渗硼后合金表面呈现为残余压应力状态,且残余压应力值随渗硼温度的升高而增大。本研究结果可为进一步研究渗硼处理对Ti-55531合金耐磨损及疲劳性能的影响奠定基础。

The effects of boronizing treatment at different temperatures on the surface microstructure, composition, hardness distribution and residual stress of Ti-55531 lamellar alloy were systematically studied.The results show that the boronized layer of Ti-55531 alloy is composed of three parts: the outer surface layer of bright white product, the transition layer of whisker-like microstructure and the original lamellar matrix.The content of the element B in the boronized layer decreases gradually from the surface to the inside.After boronizing, there is a gradient layer of Ti-B compounds in the surface layer of the alloy, which significantly increases the microhardness of the alloy, and the hardness decreases gradually from the surface layer to the core.Furthermore, the surface of the alloy after boronizing presents a state of residual compressive stress, and its value increases with boronizing temperature increasing.These results of the study can lay a foundation for further study on the effect of boronizing treatment on the wear resistance and fatigue properties of Ti-55531 alloy.