纤维方向角对超低温冷却石英纤维复合材料铣削性能的影响

石英增强聚酰亚胺树脂基复合材料是一种非均匀的各向异性材料,其加工性能高度依赖于纤维铺层方向与加工进给方向所成角度,即纤维方向角。本文通过一系列不同纤维方向角的干切削和超低温冷却铣削实验,研究了纤维方向角对表面形貌、表面粗糙度、铣削力及刀具磨损的影响。结果表明:不同纤维方向角,剪应力形式不同,切削断屑形式也不同。纤维方向角为锐角时铣削表面质量均良好,但当纤维方向角增大到90°时,切削表面质量下降,切削力变化幅度增大。相同铣削时间内,在干切削工况下,刀具磨损严重,涂层脱落面积约为测量面积的70%;而在低温切削工况下,涂层未遭到严重破坏,刀具仍处于稳定磨损阶段,刀具耐用度优于干切削工况。

Effect of Fiber Orientation on Milling Performance of SiO2 Fiber Composites in Cryogenic Cooling

SiO₂ fiber reinforced polyimide composites were heterogeneous anisotropic materials,the processing properties were highly dependent on the fiber orientation angle which is between the direction of fiber layers and the direction of processing feed.In this paper,the effects of fiber orientation angle on surface morphology,surface roughness,milling force and tool wear were studied through a series of experiments of dry cutting and ultra-low temperature cooling milling with different fiber orientation angles.The results show that the types of shear stress and styles of cutting chips are different under different fiber orientation angles.The milling surface roughness is fine when the fiber orientation angle is acute.When the fiber orientation angle increases to 90°,the cutting surface quality decreases and the cutting force increases.In the same milling time, the tool wear is serious in dry cutting,and the falling off area of coating is about 70% of the measured area. But compared to dry cutting,in ultra-low temperature cooling milling,the coating is not seriously damaged,the tool is still in a stable wear stage, and the tool durability is better than that under dry cutting condition.