钛合金Ti-6Al-4V车削加工表面硬化实验

摘要

According to surface work-hardening problem of alloy Ti-6Al-4V, by surface micro-hardness and micro-cosmic structure testing experiment on titanium alloy Ti-6Al-4V under different cutting parameters, surface work-hardening mechanism of titanium alloy Ti-6Al-4V turning is explored, and the impacting rules of cutting parameters on surface work-hardening and surface metamorphic layer are analyzed. The results show that titanium alloy Ti-6Al-4V surface layer microstructure changes significantly during the turning processing. However, the increasing of cut-ting speed does not aggravate surface work-hardening degree and makes for reducing surface degenerating layer thickness. In addition, cutting heat significantly influence surface work-hardening, the raising of cutting tempera-ture weakens strain hardening function which is created by surface layer material deformation. Micro-hardness of surface metamorphic layer is lower than subsurface, but higher than substrate.%针对钛合金Ti-6Al-4V加工表面硬化问题，通过不同切削参数下钛合金Ti-6Al-4V切削加工表面的显微硬度与微观结构检测实验研究，探索钛合金Ti-6Al-4V车削加工的表面硬化机理，分析切削参数对加工硬化与表面变质层影响规律。结果表明：进行钛合金Ti-6Al-4V车削加工时，表面层微观组织发生显著变化，但表面硬化程度不高，切削速度提高不会使表面硬化程度加剧，并有利于减少表面变质层的厚度；切削热对加工表面硬化的影响显著，切削温度升高将减弱表面层材料变形产生的应变硬化作用，表面变质层的显微硬度值低于亚表层的显微硬度值，但高于基体的显微硬度值。