刀具表面典型减摩微结构激光加工及切削性能研究

发布时间：2018-06-16 03:15

本文选题：表面微结构刀具 + 飞秒激光加工　；参考：《哈尔滨工业大学》2017年硕士论文

【摘要】：刀具磨损是机械制造加工过程中的关键问题,影响刀具寿命、加工效率和表面质量,增加加工成本。刀具切削技术在不断的改进和发展,但仍不可避免由于刀具表面与工件之间的强烈挤压与相互摩擦所造成的刀具表面磨损的问题。仿生学与摩擦学大量研究表明,摩擦副表面并不是越光滑越耐磨,表面上一定的微结构能够改善摩擦副之间的摩擦性能以及减小表面粘接磨损等。本文以此为研究方向,在刀具表面利用飞秒激光加工了典型的表面微结构,分析表面微结构的减摩机理;进行了微结构刀具的切削仿真与试验研究,探究微结构的种类及尺寸参数对切削摩擦特性的影响规律。首先,选取典型的非光滑仿生微结构,即平行沟槽、垂直微沟槽和凹坑微结构,分析了刀具表面微结构可能存在的减摩机理。然后对微结构进行设计与尺寸规划。用飞秒激光的先进加工方式,通过对飞秒激光与硬质合金YT15刀具材料的相互作用机理分析和加工工艺测试,对飞秒激光加工YT15刀具表面微结构的工艺参数优化,实现对微结构的尺寸和形貌质量的控制,分别在刀具前刀面和后刀面上制备尺寸规整、形貌质量优良的微结构其次,采用ABAQUS有限元仿真软件建立微结构刀具的正交切削三维有限元模型,分别对无微结构刀具和不同类型的微结构刀具进行切削#45钢过程进行仿真,得到不同类型的微结构及不同形貌尺寸对刀具表面应力分布以及切削力的影响,分析切削过程中的切削力、刀具表面应力分布以及切削卷屑的变化。最后,选取#45钢为工件材料,对于不同类型、不同尺寸微结构的YT15刀具进行干切削和切削液润滑不同条件下的切削对比试验。结果表明微结构对切削的改善效果不仅与微结构的种类有关,也与切削用量以及切削润滑条件相关。在较高切削速度下,切削液存在情况下,平行沟槽效果最明显,可降低切削力17.74%;对不同尺寸的微结构进行切削对比试验,得到不同类型微结构的宽度、间距、深度以及面积占有率对刀具减摩效果的影响;并对前、后刀面微结构的对切的改善效果进行了探究;分析了微结构尺寸参数对切削卷屑的影响,最终分析和总结了微结构刀具的对切削性能的改善效果。研究为微结构刀具技术的发展、进一步探索微结构作用机理提供了基础。
[Abstract]:Tool wear is a key problem in machining process, which affects tool life, machining efficiency and surface quality, and increases machining cost. Tool cutting technology is continuously improving and developing, but it is still inevitable that tool surface wear is caused by the strong extrusion and friction between the cutting tool surface and the workpiece. A large number of biomimetic and tribological studies show that the surface of the friction pair is not more smooth and wear-resistant, and a certain microstructure on the surface can improve the friction performance between the friction pairs and reduce the surface adhesion wear and so on. In this paper, the typical surface microstructure is fabricated by femtosecond laser on the tool surface, and the friction reduction mechanism of the surface microstructure is analyzed, and the cutting simulation and experiment of the micro-structure tool are carried out. The influence of the types and dimensions of microstructures on the cutting friction characteristics was investigated. Firstly, typical non-smooth bionic microstructures, namely parallel grooves, vertical microgrooves and pit microstructures, are selected to analyze the possible friction reduction mechanism of the surface microstructures. Then the design and size planning of microstructures are carried out. By analyzing the interaction mechanism between femtosecond laser and cemented carbide YT15 cutting tool material and testing the machining technology, the process parameters of femtosecond laser machining YT15 tool surface were optimized by using the advanced processing method of femtosecond laser. In order to control the size and morphology quality of the microstructures, the size of the microstructures on the front and rear face of the cutting tools were prepared respectively, and the microstructures with excellent morphology and quality were then prepared. Abaqus finite element simulation software is used to establish the 3D finite element model of orthogonal cutting of microstructural cutting tools. The process of cutting #45 steel without microstructural tools and different types of microstructural cutters is simulated respectively. The effects of different types of microstructures and different morphologies on the stress distribution and cutting force on the surface of the cutting tool were obtained. The cutting force, the stress distribution on the surface of the cutting tool and the change of the cutting coil were analyzed. Finally, #45 steel was selected as workpiece material, and YT15 cutting tools with different types and sizes were tested under different conditions of dry cutting and lubricated by cutting fluid. The results show that the effect of microstructures on cutting is not only related to the types of microstructures, but also to the cutting parameters and cutting lubrication conditions. In the case of high cutting speed, the effect of parallel grooves is the most obvious in the presence of cutting fluid, and the cutting force can be reduced by 17.74.The width and spacing of different types of microstructures are obtained by comparing cutting experiments with different sizes of microstructures. The effect of depth and area occupancy on the anti-friction effect of the cutting tool, the improvement of the cutting effect of the micro structure of the front and rear cutter face, and the influence of the parameters of the microstructural dimension on the cutting coil chip are analyzed. Finally, the effect of microstructural cutting tools on cutting performance is analyzed and summarized. The research provides a basis for the development of microstructural tool technology and the further exploration of the mechanism of microstructural action.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG71;TG665

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