钛合金TC4侧铣削刀具结构优化与刀具磨损研究

发布时间：2018-03-15 05:28

本文选题：侧铣削　切入点：C形刃立铣刀　出处：《湖南科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：钛合金以其比强度高、抗氧化性好、耐蚀性好、耐热性高等优点迅速进入航空航天领域并成为主要结构材料之一。但钛合金又是一种典型的难加工材料,在加工过程中具有导热率低、化学活性高、切削力大、刀具易磨损等问题,这必然会影响加工零件的表面完整性能,进而影响钛合金构件的疲劳性能。在钛合金的加工过程中,刀具几何参数对工件的变形、切削力和刀具磨损有重要影响。因此,研究钛合金铣削过程中刀具的几何参数具有重要意义。本文通过侧铣削钛合金试验,对整体硬质合金立铣刀几何参数展开优化设计研究。论文主要研究内容如下:(1)通过对钛合金TC4进行侧铣削加工,采用正交设计方法研究了硬质合金立铣刀侧刃几何参数对切削力和表面粗糙度的影响,用极差法分析了刀具几何参数对铣削力的影响;并以最小表面粗糙度为目标,采用田口法对刀具几何参数进行了优选。结果表明:对于主切削力Fy,螺旋角对其影响最大,C形刃角度次之,C形刃宽度的影响最小;当选择螺旋角为25°、C形刃宽度为0.2mm、角度为-25°时可获得最小表面粗糙度。(2)将优化出的立铣刀与常规立铣刀进行对比实验,分析了两种立铣刀的铣削力和表面粗糙度,验证了优化立铣刀侧铣削TC4的优良性能。结果表明:在相同的加工参数下,C形刃立铣刀的铣削力和表面粗糙度均要小于常规立铣刀。(3)研究了铣削速度对C形刃立铣刀和常规立铣刀的刀具磨损影响。结果表明:C形刃立铣刀与常规立铣刀的刀具磨损量都随铣削速度的增加而增大。在相同速度下,C形刃立铣刀刀具磨损量要低于常规立铣刀;在铣削相同距离时,C形刃立铣刀的磨损量同样低于常规立铣刀。C形刃立铣刀耐用度要高于常规立铣刀。通过扫描电镜和能谱分析对后刀面磨损进行能谱分析,结果表明:硬质合金立铣刀侧铣削钛合金的磨损机理有粘结磨损、扩散磨损和氧化磨损。
[Abstract]:Titanium alloys have rapidly entered the aerospace field and become one of the main structural materials because of their high specific strength, good oxidation resistance, good corrosion resistance and high heat resistance. In the process of machining, problems such as low thermal conductivity, high chemical activity, large cutting force and easy wear of cutting tools will inevitably affect the surface integrity of machined parts and then affect the fatigue properties of titanium alloy components. The geometric parameters of the cutting tool have an important effect on the deformation, cutting force and tool wear of the workpiece. Therefore, it is of great significance to study the geometric parameters of the cutting tool in the milling process of titanium alloy. The optimization design of geometric parameters of monolithic cemented carbide end milling cutters is studied. The main contents of this paper are as follows: (1) side milling of titanium alloy TC4 is carried out. The influence of side edge geometry parameters on cutting force and surface roughness of cemented carbide end milling cutter is studied by orthogonal design method. The influence of cutting tool geometry parameters on milling force is analyzed by the range method, and the minimum surface roughness is taken as the target. The geometric parameters of the cutting tool are optimized by the Taguchi method. The results show that for the main cutting force FY, the helical angle has the least effect on the width of the C-shaped edge, followed by the angle of the C-shaped edge. When the helical angle is 25 掳C edge width is 0.2 mm, and the angle is -25 掳, the minimum surface roughness can be obtained.) the optimized end milling cutter is compared with the conventional end milling cutter, and the milling force and surface roughness of the two kinds of end milling cutters are analyzed. The results show that the milling force and surface roughness of the C edge end milling cutter are lower than that of the conventional end milling cutter under the same machining parameters. The results show that the wear of the end milling cutter with C edge increases with the increase of milling speed, and the wear of the end milling cutter with C edge is lower than that of the conventional end milling cutter at the same speed. When milling at the same distance, the wear amount of C edge end milling cutter is also lower than that of conventional end milling cutter. The wear of the end milling cutter with C edge is higher than that of the conventional end milling cutter. The wear of the rear face is analyzed by energy dispersive microscope and energy spectrum analysis. The results show that the wear mechanism of cemented carbide side milling titanium alloy is adhesive wear, diffusion wear and oxidation wear.
【学位授予单位】：湖南科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG54;TG714

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