基于热力学的聚晶立方氮化硼刀具切削镍基合金的磨损机理

文章通过切削实验研究了聚晶立方氮化硼刀具切削镍基合金的磨损机理。运用热力学基本理论推导了物质吉布斯自由能函数法,并应用到刀具前刀面氧化磨损的分析中。计算了刀具表面极易发生的化学反应的吉布斯自由能,并分析得出了发生氧化磨损的主要氧化反应方程式。运用扩散第一定律分析了刀具发生扩散磨损的机理,得出了刀具前、后刀面扩散磨损过程发生机理的差异性。运用SEM扫描电镜对刀具表面进行了化学磨损分析。结果表明,刀具前、后刀面都发生了严重的氧化、扩散以及化学磨损,刀具表面发生了严重的放氮反应。研究内容可为加工镍基合金提高刀具寿命提供参考。

Wear Mechanism of Polycrystalline Cubic Boron Nitride Tools Based on Thermodynamics for Cutting Nickel-Based Alloys

In this paper,the wear mechanism of polycrystalline cubic boron nitride tool for cutting nickel-based alloys was studied by cutting experiments.The material Gibbs free energy function method is derived by using the basic theory of thermodynamics and applied to the analysis of the oxidative wear of the tool rake face.The Gibbs free energy of the chemical reaction that is easy to occur on the tool surface is calculated,and the main oxidation reaction equation for oxidative wear is analyzed.The first law of diffusion is used to analyze the mechanism of diffusion wear of the tool,and the difference of the mechanism of the diffusion process before and after the tool face is obtained.Chemical wear analysis of the tool surface was performed using SEM scanning electron microscopy.The results show that the front and back flank of the tool have serious oxidation,diffusion and chemical wear,and the surface of the tool has a serious nitrogen release reaction.The research content can provide reference for processing nickel-based alloys to improve tool life.