Ti6Al4V高速切削过程有限元模拟及切削参数优化

发布时间：2018-05-22 19:02

本文选题：高速切削 + 有限元仿真　；参考：《昆明理工大学》2017年硕士论文

【摘要】：钛合金材料力学性能优异,并且耐腐蚀性好材料密度较低,因此是航空航天工业零部件生产中主要的消费材料。然而由于钛合金的弹性模量小、高温化学活性高和导热系数低等特性,又使得钛合金成为一种较为典型的难加工材料。在钛合金材料的高速切削加工过程中,很容易出现切削温度过高的情况,这会导致工件表面质量难以控制、切削刀具磨损加快,而降低切削速度又会引起加工效率下降不利于生产。同时,大型的航空零件在设计时大多以整体设计特点为主,生产加工时多数材料都要从工件毛坯中切除,这就引起工件加工成本较高。尽管,通过3D打印技术生产出来的钛合金零件在一些特殊领域得到应用,但是由于成本很高并不适合大规模生产。所以,实现钛合金的快速、高效切削加工是目前航空制造工业领域中迫切需要解决的问题。本文主要是从刀具几何参数的角度去解决钛合金Ti6A14V加工中的切削力过大和切削温度过高的问题,以尽可能降低切削温度和切削力为目标,从而求得优化后的刀具几何参数组合。本文通过对钛合金材料高速切削研究现状和高速切削加工理论进行研究,了解到切削过程有限元模拟的一些关键技术。对刀-屑摩擦模型、切屑分离准则、材料本构模型等关键技术分析后,利用专业的切削仿真软件AdvantEdge建立了硬质合金材料刀具高速切削钛合金Ti6A14V的三维正交切削有限元模型,并通过变换刀具几何参数(前角γ0、后角α0、钝圆半径rε)进行模拟仿真得到不同参数组合下的切削力与切削温度数据,分析得出了各个参数对切削力与切削温度的影响规律。利用二阶响应面法对仿真模拟得到的不同刀具几何参数下的多组切削温度与切削力数据进行拟合,得到了刀具几何参数与切削温度和切削力之间的函数关系模型。然后,在对刀具几何参数的取值范围进行约束的基础之上,利用遗传算法优化程序优化计算,得到了适合Ti6A14V材料的硬质合金材料刀具几何参数组合。该参数组合下切削温度的数值范围都在较为合理的范围内,远离了硬质合金的软化温度,能够充分的发挥刀具的切削性能。根据优化结果定制切削刀具进行切削实际试验,试验结果表明优化后的切削力与切削温度数据比较理想。
[Abstract]:Titanium alloy has excellent mechanical properties and low density of corrosion-resistant materials, so it is the main consumption material in the production of aerospace industry parts. However, because of its low elastic modulus, high chemical activity at high temperature and low thermal conductivity, titanium alloy has become a typical refractory material. In the process of high speed cutting of titanium alloy material, it is easy to appear the situation that the cutting temperature is too high, which will lead to the hard to control the surface quality of the workpiece, and the wear of cutting tool will be accelerated. And lower cutting speed will lead to the decline of machining efficiency is not conducive to production. At the same time, most of the large aeronautical parts are designed with the overall design characteristics, and most of the materials must be removed from the workpiece blank in the production and processing, which leads to the higher processing cost of the workpiece. Although titanium alloy parts produced by 3D printing technology have been applied in some special fields, they are not suitable for mass production because of their high cost. Therefore, the rapid and efficient cutting of titanium alloy is an urgent problem in the field of aviation manufacturing industry. In this paper, the problem of too large cutting force and too high cutting temperature in Ti6A14V machining of titanium alloy is solved from the angle of tool geometry parameters. The aim of this paper is to reduce cutting temperature and cutting force as far as possible, so as to obtain the optimized combination of tool geometry parameters. In this paper, the research status of high speed cutting of titanium alloy material and the theory of high speed cutting are studied, and some key techniques of finite element simulation of cutting process are found out. After analyzing the key technologies such as the tool chip friction model, chip separation criterion and material constitutive model, the 3D orthogonal cutting finite element model of Ti6A14V for high speed cutting of titanium alloy with cemented carbide cutting tool was established by using the professional cutting simulation software AdvantEdge. The cutting force and cutting temperature data are obtained by changing the geometric parameters of the cutting tool (the front angle 纬 0, the rear angle 伪 0, the blunt circle radius r 蔚), and the influence of each parameter on the cutting force and cutting temperature is analyzed. The second order response surface method is used to fit the multi-group cutting temperature and cutting force data under different tool geometry parameters, and the function model of tool geometry parameters and cutting temperature and cutting force is obtained. Then, on the basis of constraining the range of geometric parameters of cutting tools, the optimum calculation program of genetic algorithm is used to obtain the combination of geometric parameters of cemented carbide materials suitable for Ti6A14V materials. The numerical range of cutting temperature under the combination of these parameters is in a reasonable range, which is far from the softening temperature of cemented carbide and can give full play to the cutting performance of the cutting tool. According to the optimized results, the cutting tool is customized for actual cutting test. The experimental results show that the optimized cutting force and cutting temperature data are ideal.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG506.1

【相似文献】