Though there are already a varlety of models for comples, they are not so convenientneeded in practice. A hlerchical model and the principle of decomposition and reconstitution for complex surfaceshave beem proposed, which have the potential to enhance the support of automated design systems on creative work intelligently. Then the progress made is discused involving the application of the new principle in the following threeareas; conugation sudace calculation, tool path generation in numercally controlled machining, and maching proccessinnovation By re-recognition.

An experimental investigation is carried out to coat two types of carbide powders, TiC and (W, Ti) C, with an alumina ceramic using a sol-gel technology. The coated carbide powders are then fabricated into two kinds of new ceramic tool materials by the hot pressing method. A scanning electron microscopy (SEM) observation reveals that the matrix (carbide) grains are uniformly coated with the alumina ceramic and the new tool materials have a homogeneous microstructure. The tests of mechanical properties and wear resistance in machining are finally conducted. It is shown that the new tool materials can increase the tool-life by up to 100% as compared to other ceramic tool materials when machining a mild carbon steel, while the fracture toughness is improved by up to 33%. When compared with a hard coated carbide tool, the new materials exhibit a superior ability in maintaining the wear resistance during the entire tool-life.

A new ceramic cutting fool material has been developed by means of silicon carbide whisker (SiCw) reinforcement and silicon carbide particle (SiCp) dispersion. The material has the advantage of high bending strength and fracture tougbness. Compared with the mechanical properties of Al2O3(A), Al2O3/SiCp(AP), Al2O3/SiCw(AW), Al2O3/SiCw(JX-1) and Al2O3/SiCp/SiCw(JX-2), it confirms that JX-2 composite has obvious additive effect of both reinforcing and toughening. The reinforcing and toughening mechanisms of JX-2 composite have been studied based on the analysis of thermal-expansion mismatch and the observation of microstructure, Synergistic effects of toughening and strengthening for JX-2 have been researched systematically.

A review of advanced ceramic tool material, including its development, app]ication and the new trend in research, is offered in this article. As one of the most important tool materials to be used in the next century, advanced ceramic material has great potential and broad prospects. The major subject in the future study is the development of new type of ceramic tool material and finding ways to increase its strength and toughness as well as its reliability. The imperative task at present is how to popularise ceramic tools and how to use them more efficiently and reasonably.

Better and more capable tool materials allow machine tools to cut at increasingly higher speeds and feeds. Inrecent decades, high speed machining has received an important interest as a technological solution for high productivityto increase economic efficiency in manufacturing. The recent developments of cutting tool materials in high speed ma-chining are reviewed. The appropriate applications of the high speed machining technology are presented. It can concludethat the optimal matching of meehardcal, physical, end chemical properties between teol and workpieee materials is veryimportant in high speed machining. The researeh is very grit beneficial to the design and the selection of re431 materials hihigh speed machining.