高速钢车刀激光熔覆断屑台制备方法的研究

发布时间：2018-06-05 08:06

本文选题：高速钢车刀 + 激光熔覆　；参考：《宁波大学》2017年硕士论文

【摘要】：车削加工中,连续不断的切屑会影响工件表面质量,减少刀具寿命,危及到操作人员的安全。本文应用激光熔覆技术在高速钢车刀的前刀面上制作出无裂纹、气孔缺陷的凸包形断屑台,研究其制作工艺和方法。首先,通过车削LY12硬铝合金实验证明激光熔覆断屑台高速钢车刀断屑效果优于普通高速钢车刀,能够获得较高的加工表面质量,但是熔覆断屑台截面有裂纹、气孔、冶金结合不良等缺陷。通过析因实验设计的方法,研究激光工艺参数对熔覆裂纹缺陷的影响,建立了裂纹率与工艺参数之间的回归方程。研究表明,熔覆工艺参数对裂纹的影响程度依次为电流、脉宽、频率、扫描速度、离焦量,此外,熔覆裂纹的产生还受到工艺参数间交互作用的影响。然后,通过对几种熔覆粉末的激光熔覆实验,确定出适于W6Mo5Cr4V2刀具材料的熔覆粉末材料,即利用混入质量分数为15%WC-12Co的M2高速钢粉末激光熔覆制作的断屑台其显微硬度较高,熔覆截面无裂纹、气孔等缺陷,并通过热膨胀系数、XRD物相、硬度分析、金相组织分析等手段来解释说明熔覆裂纹消除的原因。最后,通过单因素实验方法研究了激光工艺参数对熔覆凸包几何尺寸的影响规律,并且利用正交实验的方法对熔覆凸包的激光工艺参数进行了优化。
[Abstract]:During turning, the continuous chip will affect the surface quality of the workpiece, reduce the tool life and endanger the safety of the operator. In this paper, the laser cladding technique is used to fabricate the convex cladding chip table without crack and pore defect on the front face of high speed steel turning tool, and the fabrication technology and method are studied. Firstly, the experiment of turning LY12 hard aluminum alloy shows that the chip breaking effect of high speed steel turning tool of laser cladding chip table is better than that of ordinary high speed steel turning tool, and the surface quality of machined surface can be obtained, but there are cracks and pores in the cross section of cladding chip table. Defects such as poor metallurgical bonding. The effect of laser process parameters on cladding crack defects was studied by factorial experiment. The regression equation between crack rate and process parameters was established. The results show that the influence of cladding process parameters on the crack is in order of current pulse width frequency scanning speed and defocus. In addition the process parameters also influence the production of the cladding crack. Then, through the laser cladding experiment of several kinds of cladding powder, the cladding powder material suitable for W6Mo5Cr4V2 tool material is determined, that is, the microhardness of the chip breaking table made of M2 high speed steel powder cladding with mixed mass fraction of 15%WC-12Co is high. The cladding section has no defects such as cracks, pores, and so on. The reasons for the elimination of cladding cracks are explained by means of thermal expansion coefficient XRD, hardness analysis and metallographic structure analysis. Finally, the influence of laser parameters on the geometrical size of cladding convex hull is studied by single factor experiment, and the laser technological parameters of cladding convex hull are optimized by orthogonal experiment.
【学位授予单位】：宁波大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG174.4;TG712

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