钛合金切削振动特性及对表面粗糙度影响的研究

发布时间：2018-07-18 09:17

【摘要】：切削加工过程中会产生各种形式的振动,各种形式的振动综合起来,最后作用于刀具上,引起刀具的振动,这是一种难以避免的正常现象,但通常是有害的。并且高频的振动会增大表面粗糙度。因此,研究切削振动对表面粗糙度的影响是很有必要的。本文通过理论分析、试验研究及有限元模拟相结合的方法对车削加工时刀具振动、表面粗糙度进行研究。主要研究的内容和结果如下:(1)选择TA15、TC4钛合金进行单因素和正交干式车削试验。以振动加速度有效值描述振动特性,研究了切削用量对振动的影响规律,探讨了切削力对振动的影响、切屑形态对振动的影响,通过对绝热剪切扩展能的理论计算和试验研究,来研究钛合金绝热剪切敏感性和振动之间的关系。研究结果表明:切削深度对振动的影响最大,其次是进给量,切削速度的影响是最小的;切削振动和切削力有一定的关系,两者的变化趋势相似;刀具的高频振动会引起切削力的波动,切削力的波动反过来也会导致刀具的振动,两者相互作用,共同影响;绝热剪切扩展能(38)值越小,绝热剪切敏感性越强,越容易产生锯齿形切屑,振动越大。反之,振动越小。(2)通过TA15、TC4钛合金的表面粗糙度试验,研究切削用量对表面粗糙度的影响,并探讨振动对表面粗糙度的影响。研究结果表明:进给量对表面粗糙度影响最大,其次是切削深度,切削速度影响最小;实际加工时的表面粗糙度是理论粗糙度和刀具振动相互叠加的结果,其中理论粗糙度是刀具几何参数和切削用量对表面粗糙度的影响。(3)利用有限元软件ABAQUS对高速车削钛合金Ti-6Al-4V切削过程做了仿真分析,特别是从总能量的角度对振动过程及锯齿形切屑的形成过程进行了分析。得到的主要结论:锯齿形切屑总能量图不断在上升说明了切削过程是个有规律的振动的过程;能量图与锯齿形切屑形成的规律具有一致性,因此锯齿形切屑的产生会导致刀具的高频振动。(4)通过小波分析和SPSS软件来研究振动和表面粗糙度之间的关系。研究结果表明:振动是影响表面粗糙度的主要动态因素,振动和表面粗糙度两者相关性较强,变化趋势具有一致性。
[Abstract]:In the process of cutting, various forms of vibration can be produced. The vibration of various forms is combined, and finally acts on the tool to cause the vibration of the tool. It is an unavoidable normal phenomenon, but it is usually harmful. And the vibration of high frequency will increase the surface roughness. The main research contents and results are as follows: (1) select TA15, TC4 titanium alloy for single factor and orthogonal dry turning test. The vibration acceleration is used to describe the vibration characteristics, The influence of cutting amount on vibration is studied. The influence of cutting force on vibration and the influence of chip shape on vibration are discussed. The relationship between the adiabatic shear sensitivity and vibration of titanium alloy is studied by theoretical calculation and experimental study of the adiabatic shear expansion energy. The results show that the cutting depth has the greatest influence on the vibration. The second is the feed, the cutting speed has the smallest influence; the cutting vibration and the cutting force have a certain relationship, the changing trend of the two is similar; the high frequency vibration of the cutting tool will cause the fluctuation of the cutting force, and the fluctuation of the cutting force will in turn result in the vibration of the cutting tool. Both of them interact with each other; the adiabatic shear expansion energy (38) is smaller and adiabatic. The stronger the shear sensitivity, the more easy to produce the sawtooth chip, the greater the vibration. On the contrary, the smaller the vibration. (2) through the surface roughness test of TA15, TC4 titanium alloy, the effect of the cutting amount on the surface roughness is studied and the influence of the vibration on the surface roughness is discussed. Cutting depth has the smallest effect on cutting speed; the surface roughness in actual processing is the result of the overlapping of theoretical roughness and tool vibration, and the theoretical roughness is the effect of tool geometric parameters and cutting parameters on the surface roughness. (3) the simulation of high speed turning titanium alloy Ti-6Al-4V cutting process is made by using the finite element software ABAQUS. Analysis, especially from the point of view of the total energy, the forming process of the vibration process and the sawtooth chip is analyzed. The main conclusion is that the total energy diagram of the sawtooth tangent is constantly rising, which indicates that the cutting process is a regular vibration process; the energy map is consistent with the law of the sawtooth shaped chip form, so the sawtooth chip is in the shape of the sawtooth shape. (4) the relationship between vibration and surface roughness is studied by wavelet analysis and SPSS software. The results show that vibration is the main dynamic factor affecting surface roughness, and the correlation between vibration and surface roughness is strong, and the trend of the change is consistent.
【学位授予单位】：沈阳理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG501;TG146.23

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