A Research Of The Application Of PCBN Tools

Cutting is one of the important processes in mechanical manufacture. With the advancement of information technology, the traditional cutting technology has been replaced by modern cutting technology gradually. Manufacture enterprises have made great profits from the application of modern cutting technology— hard turning, high speed cutting and dry cutting. For the wide application of the modern technology, the wide application of new cutting material is an important factor. The high speed steel cutting tools that are used broadly in traditional cutting have been totally replaced by carbide tools, ceramic tools, coated tools and super-hard tools. PCBN is one kind of the important superhard tool materials and is widely supposed to be an ideal tool material for modern cutting technology. But its degree of application in China is far behind from that in advanced countries.In the chapter of introduction, this thesis concisely outlines the situation of different aspects of modern cutting technology, and also reviews the history of development and application of the new cutting material. In the chapter two, the thesis introduces the manufacture of PCBN tools and its excellent cutting abilities, moreover, it presents a comprehensive outline in the two main research fields of the PCBN tools. In the third chapter , the problem about designing the PCBN tools is detailedly discussed. Through the data from the orthogonal cutting experiments, the conclution can be concluded that the cutting tool geometry parameters that affect the tool life of PCBN tools in turning are the honed edge at the bottom of the chamfer, the degree of chamfer, the lead angle and the radius of cutting tip. It is also found that the speed of tool wear will increase greatly after the tool cuts the grey ironexceeding to some extent. In the chapter four, this thesis makes a research of the problem of building a mathematical production model, and puts up a new model that is based on tool reliability and oriented for the objective of max production rate. According to the experimental data from other researchers' work, it presents a formulation that can be used for the computation of the PCBN tool reliability with the variation of cutting data and using time. In the fifth chapter, an objective function is definited from the mathematical model built in the chapter four firstly, then optimizing the cutting parameters is done by the niched GA when the PCBN tool borings the motor hole of block made in HT250. It is obvious that the cutting parameters optimized can bring more economic profits compared with the original cutting parameters.