SiCp/Al-Ti叠层复合材料表面切削损伤形成机制

Formation mechanisms of surface cutting damage in SiCp/Al-Ti laminated composites

关键词:  叠层复合材料  材料性能  切削损伤  去除机制  表面质量

Key words:  laminated composites  material properties  cutting damage  removal mechanism  surface quality

摘要:

SiCp/Al-Ti叠层复合材料通过铝合金和钛合金的层状复合及SiC颗粒增强,达到高强韧性、高稳定性及轻量化等性能,可实现关键部件的性能加强与应用,但同时也容易因材料内部性能差异导致切削损伤等质量问题。本文考虑SiCp/Al-Ti叠层材料的异质材料层性能及颗粒-层间多相界面特性,首先建立了基于异质材料和双线性内聚力界面的切削仿真模型,探究了不同切削工艺下的切削力-热变化,并利用二维切削实验平台验证了仿真模型的差异性在10%以内；通过仿真分析及表面SEM观测,研究了叠层复合材料在不同切削工艺条件下的材料去除过程,揭示了切削损伤的形成机制；最后采用表面三维形貌的分区域表面粗糙度计算方法,探究了切削参数对表面质量的影响规律。结果表明,刀具从TC4层切入SiCp/Al层时,强度高的TC4使SiCp/Al产生层间弯曲变形,损伤形式主要为分层裂纹和层间颗粒压碎；当刀具从SiCp/Al层切入TC4层时,则会出现SiCp/Al层涂覆层间界面,损伤形式主要为界面涂覆和颗粒压入界面,且由于SiC颗粒的存在,加工SiCp/Al层损伤比TC4层缺陷更为严重。

Abstract:

SiCp/Al-Ti laminated composites achieve the properties of high toughness, high stability and lightweight through laminated aluminum alloy, titanium alloy and the reinforcement of SiC particles,facilitating the enhancement of key components. However, the inherent differences in material properties can lead to cutting damage and other quality issues. In this study, considering the heterogeneous material properties and multiphase interface characteristics of SiCp/Al-Ti materials, a cutting simulation model based on heterogeneous materials and bilinear cohesive interfaces is established to explore the cutting force-heat changes in different cutting processes. The simulation model is validated by a two-dimensional cutting experimental platform, demonstrating discrepancies within 10%.Then, the material removal process of laminated composites under different cutting conditions is investigated through simulation analysis and surface SEM observation, revealing the formation mechanisms of cutting damage. Finally, the subarea surface roughness calculation method of 3D morphology is adopted to explore the influence law of cutting parameters on surface quality.The results show that when the tool cut from the TC4 to the SiCp/Al layer, the high strength of TC4 induces interlaminar bending deformation in the SiCp/Al, resulting in damage primarily characterized by delamination cracks and interlaminar particle crushing.Conversely, when the tool cut from the SiCp/Al into the TC4 layer, the interfacial coating of the SiCp/Al layer is affected, leading to damage predominantly manifested as interfacial coating failure and particle indentation at the interface. Furthermore, due to the presence of SiC particles, the machining of the SiCp/Al layer damage is more serious than that of the defects in the TC4 layer.