磨粒磨损对砂带磨削TC17表面完整性的影响研究

Study on Influence of Abrasive Wear on Surface Integrity of TC17 Grinding by Abrasive Belt

砂带磨粒磨损直接影响磨削表面质量进而影响构件综合服役性能。以表面完整性为评估指标,对砂带磨损前后钛合金的表面加工质量进行了试验研究,揭示了砂带磨粒磨损对磨削TC17表面粗糙度、残余应力和表面硬度的影响规律及机制。结果表明,磨粒磨损后由于高度均匀化、单位面积切削磨粒数增加、磨削深度减小,使得表面粗糙度减小、纹理均匀细腻,粗糙度降低可达70.3%。与磨损磨粒相比,锋利磨粒砂带加工表面材料发生了明显加工硬化,使表面硬度提升达到20%以上,而磨损磨粒加工表面发生了塑性涂敷,显微硬度略低于基体硬度。试验中,砂带磨削表面均实现了残余拉应力(约400MPa)向残余压应力(-300MPa左右)的转变。不同砂带的磨粒磨损对表面残余压应力的影响不同,锆刚玉砂带磨粒磨损使磨削表面残余压应力提升了33%,金刚石砂带磨粒磨损使磨削表面残余压应力降低了34%。

Abrasive belt abrasive wear will affect the surface quality of the grinding,and then affect the service performance of the grinding components.This paper uses the surface integrity as the evaluation index to evaluate the grinding quality of the abrasive belt before and after abrasive wear,and analyzes the effect of abrasive wear on the surface roughness,residual stress and surface micro-hardness of the abrasive belt grinding TC17.Results show that:after the abrasive grains are worn,due to the uniformity of the abrasive grains,more abrasive grains per unit area actually involved in cutting,grinding depth reduced.The grinding texture is uniform and fine,and the roughness decreases up to 70.3%.Compared with worn abrasive grains,the machined surface of sharp abrasive belts has undergone significant plastic deformation,and the hardness of abrasive abrasive belt surface can be increased to more than 20%by work hardening.On the other hand,the material plastic flow occurs on the surface processed by wore abrasive belt,so the surface microhardness is slightly lower than the matrix hardness.In this experiment,grinding surface has realized the transformation of residual tensile stress(about 400 MPa)to residual compressive stress(about-300 MPa).The abrasive wear of different abrasive belts has different effects on surface residual stress.Abrasive wear of zirconium corundum abrasive belt increases surface residual compressive stress by 33%,and abrasive wear of diamond abrasive belt reduces surface residual compressive stress by 34%.