Research On Machining Of Titanium Alloy Using Cutting Tool With Surface Texture

Rapid wear of the cutting tool greatly reduces the cutting tools life, cutting efficiency and machining accuracy in the cutting process of Ti6Al4 V titanium alloy. Therefore, the improvement of friction properties on the interface of tool-chip has a great practical significance. Presently, the research of the cutting tool with surface texture reveals that surface texture combined with certain lubrication conditions can effectively reduce cutting force, cutting temperature and friction coefficient of tool-chip interface, which provides a possible way to restrain tool wear in the cutting process of titanium alloy. In this paper, the cemented carbide(YG8)and the polycrystalline diamond(PCD)were selected as the cutting tool material for fabricating surface texture, and fundamental research of the effect of the micro-grooved tool on machining of titanium alloy process were carried out under dry cutting conditions and cryogenic MQL conditions, respectively. The major research works are included as follows:(1)The shape and parameter range of the micro-groove array on the rake face of cutting tool were designed. A three-dimensional finite element model of orthogonal cutting of titanium alloy with the micro-grooved tool was created. In order to reduce the dimension error and improve the accuracy during the process of laser machining of micro-grooves, a research work on the platform of fabricating the micro-grooved cutting tool was carried out.(2)The YG8 and PCD were selected as the cutting tool materials, and the effect of the processing parameters of the fiber laser on machining of the micro-groove array was studied by a self-built platform of laser processing. Based on this basis, the control of the dimension and the topography of the micro-groove were successfully achieved by the comprehensive optimization of laser process parameters.(3)The experiments of orthogonal cutting of Ti6Al4 V titanium alloy were respectively carried out to study the effect of the conventional YG8 tools,the micro-grooved YG8 tools, the conventional PCD tools, the micro-grooved PCD tools and the micro-groove arrary parameters of YG8 tools surface on cutting force, average friction coefficient and anti-adhesion effect during the process of machining of titanium alloy under dry cutting conditions and cryogenic MQL conditions. According to the results of simulations and experiments, the effect of the micro-grooved tools and the conventional tools on friction condition of the tool-chip interface was contrasted and analyzed under dry cutting condtions.(4)The effect of the micro-grooved YG8 tools and the micro-grooved PCD tools on the reducing the cutting friction was contrasted and analyzed, and the cutting action mechanism of the micro-grooved tools was discussed and revealed by tool-chip contact length, formation of lubricating film on the tool-chip interface and the formation of TiC protective layer on the rake face of tools.