刀具走刀方式对TC11薄壁件铣削表面质量影响规律研究

目的研究TC11薄壁件铣削加工过程中刀具走刀方式对加工表面质量的影响规律。方法采用单因素试验法,进行了钛合金薄壁件的铣削试验,得到了TC11薄壁件铣削刀具走刀方式对表面粗糙度、表面残余应力和表面显微硬度的影响规律。结果对于TC11薄壁件铣削,HU(水平向上)走刀方式获得的表面粗糙度为0.46μm,VU(垂直向上)走刀方式获得的表面粗糙度为0.74μm。两种走刀方式获得的表面残余应力均为压应力,VU走刀方式下的残余应力比HU走刀方式下的残余应力大。另外,随着加工深度的增加,两种走刀方式获得的残余应力值都减小,HU走刀方式下试件的残余应力影响层深度为65μm,VU走刀方式下的残余应力影响层深度为43μm。两种走刀方式下的显微硬度均呈现先软化再硬化,最后趋近于基体硬度的趋势,VU走刀方式下工件的硬化程度比HU走刀方式下稍严重。结论刀具的走刀方式对TC11薄壁件铣削加工表面各特征量的影响规律不相同。对于加工表面粗糙度,HU走刀方式能够获得更好的加工表面粗糙度。对于加工表面残余应力,两种走刀方式获得的残余应力属性相同,但数值不同。随着加工深度的增加,两种走刀方式获得的残余应力变化规律相同,但最大影响深度有所区别。对于加工表面显微硬度,两种走刀方式的影响规律一致,但工件的硬化程度有所区别。

Effect of Tool Path Mode on Milled Surface Quality of TC11 Thin-walled Parts

The work aims to study law of influence of tool path mode on surface quality of TC11 thin wall parts during mil-ling. Milling test was performed to TC11 thin-walled parts in the method of single-factor test. The law of influence of tool path mode on surface roughness, surface residual stress, surface microhardness of TC11 thin-wall parts was obtained. The surface roughness of TC11 thin-walled parts milled in HU (Horizontal Upward) tool path mode was 0.46μm, and in VU(Vertical Up-ward) tool path mode 0.74μm. Surface residual stress of TC11 thin-walled parts milled in either HU or VU mode was compres-sive stress, and the surface residual stress of parts milled in VU mode was higher than that in HU tool path mode. In addition, the residual stress of parts milled in both modes decreased with the increase of cutting depth. The depth of layer affected by re-sidual stress in HU mode was 65μm, and in VU 43μm. Lastly, surface microhardness of the parts milled in both tool path mod-es first softened and then hardened, and was finally close to substrate hardness. Hardening level of workpieces milled in VU mode was worse than that in HU mode. Laws of influence of tool path mode on surface characteristics of TC11 thin-walled workpieces vary a lot. For machined surface roughness, milling in HU mode leads to better surface roughness; for machined surface residual stress, properties of residual stress obtained in both tool path modes are the same, but the values are different. Moreover, with the increase of machining depth, change rule of residual stress in both tool path modes is the same, but the maximum influence depth differs from each other. For microhardness of milled surface milled in both tool path modes, the in-fluence law is consistent, but the hardening degree of workpieces is different.