Zr基大块金属玻璃切削机理研究

发布时间：2018-08-25 07:29

【摘要】：Zr基块体金属玻璃(bulk metallic glasses,简称BMG)是一种非晶体金属,具有高强度、高硬度、高断裂韧性、较低的热膨胀系数、较低的密度、良好的耐腐蚀性和抗高能粒子辐射等优异的力学性能和物理性能,是一种极具应用潜力的新型功能结构材料。但Zr基块体金属玻璃的特点是室温脆性而且硬度高,给切削加工带来了极大的困难。本文以Zr_(41.2)Ti_(13.8)Cu_(12.5)Ni_(10.0)Be_(22.5)块体金属玻璃(以下简称为Vit1)为对象,对其切削性能及切屑进行分析和研究。为了了解金属玻璃的切削力学特性,以Vit1和45钢为对比试样,通过正交实验探明切削参数对切削力的影响,并利用线性回归方法建立了实验条件下的铣削力经验公式。实验结果表明:Vit1的Y轴铣削力最大,X轴最小;而且Y轴铣削力受铣削参数变化影响最大,其次为X轴,Z轴则几乎不受影响;轴向切削深度和径向切削深度对铣削力的影响明显,进给量和切削速度的影响较小。采用硬质合金刀具在无切削液的条件下对Vit1进行切削加工,研究切屑及微观形态。结果显示:Vit1切屑是带状连续形;Vit1切屑剪切带的出现和发展是一个热量变化的过程,剪切带热量变化巨大、不固定是Vit1的塑性变形的原因。通过正交实验研究Vit1高速切削参数对切削表面粗糙度的影响。实验结果显示:Vit1高速铣削表面粗糙度的影响因素从大到小依次是进给量速度轴向切削深度.;为了取得较好的表面粗糙度,应该选取小的进给量,高的主轴转速,合适的轴向切削深度。
[Abstract]:Zr bulk metallic glass (bulk metallic glasses,) is an amorphous metal with high strength, high hardness, high fracture toughness, low coefficient of thermal expansion and low density. Excellent mechanical and physical properties, such as good corrosion resistance and high energy particle radiation resistance, are a new type of functional structural materials with great potential for application. However, Zr based bulk metallic glass is characterized by brittleness at room temperature and high hardness, which brings great difficulties to cutting. In this paper, Zr_ (41.2) Ti_ (13.8) Cu_ (12.5) Ni_ (10.0) Be_ (22.5) bulk metallic glass (hereinafter referred to as Vit1) is used to analyze and study its cutting performance and chip. In order to understand the cutting mechanical properties of metallic glass, the effect of cutting parameters on cutting force was investigated by orthogonal experiment with Vit1 and 45 steel as contrast samples. The empirical formula of milling force under experimental conditions was established by linear regression method. The experimental results show that the maximum milling force of Y axis of Vit 1 is the smallest of X axis, and the milling force of Y axis is the most affected by milling parameters, the second is that the cutting force of X axis Z axis is almost unaffected, the axial cutting depth and radial cutting depth have obvious influence on milling force. The effect of feed rate and cutting speed is small. Vit1 was machined with cemented carbide tools without cutting fluid. Chip and microcosmic morphology were studied. The results show that the appearance and development of the shear band of the Wv1 chip is a process of heat change. The shear band changes greatly and the instability is the reason of the plastic deformation of Vit1. The influence of Vit1 high speed cutting parameters on cutting surface roughness was studied by orthogonal experiment. The experimental results show that the influence factors of surface roughness in high speed milling of Vit 1 are feed speed axial cutting depth from large to small. In order to obtain better surface roughness, small feed rate and high spindle speed should be selected. Appropriate depth of axial cutting.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TG139.8

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