Research Of Mechanism And Process For Slicing ?-alumina Ceramic Based On Different Cooling Methods

Ceramic,a high-sintered conventional inorganic nonmetallic material,has a long history in machinery,electronics,and biological applications.But modern concept of ceramic has been far beyond the traditional ceramics category along with the rapid development of modern materials science.Compared with other materials,the new-type ceramic with precise control of process structure and new chemical elements has a lot of overwhelming characteristics,such as perform good electrically resistive,small high-temperature creep resistance,wear resistance,corrosion resistance,high strength,high hardness and a variety of sensitivity.Therefore,ceramic is also widely used in the aerospace,energy,biotechnology,metallurgy,electronics,optics and other industries.According to functional applications,new ceramic material can be divided into three categories: functional ceramics,structural ceramics,and bio-ceramics.As a representative of new ceramic,?-alumina ceramics is the most extensively used one.It not only used for the production of IC substrates,bionic human bones,tools,knives matrix material,but also for aviation rocket high temperature protection,abrasive powder.As a typical hard and brittle material,?-alumina ceramics is restricted to traditional machining methods because of its high hardness and brittleness.Ceramic's small range of allowable shearing stress make it difficult to process for conventional machining tool during the cutting,grinding and polishing process.It may easily crumble in operation which leads to high demand of slicing surface with lower surface roughness,no scratches and damage metamorphic layers.To solve the mentioned machining difficulties,this paper focus on reciprocating diamond wire saw technology in ?-alumina ceramic processing with advantages of a large working range,high efficiency,good processing quality,narrow kerf,good flatness,low material loss and low pollution.And do the following studies by reciprocating diamond wire saw cutting experimental work and simulation analysis:1.The development situation of diamond wire saw technology and machining status of the ?-alumina ceramics and other hard-brittle materials is sketched in the paper.The formation of cracks and removal principle of materials in ?-alumina ceramics cutting process with single diamond abrasive is elaborated based on thermodynamic theory and fracture mechanics theory.The principle is similar to grinding material removal mechanism,which is use physical model to describe mechanism of the ?-alumina ceramic sawing withsingle particle diamond abrasive and utilize the finite element software to simulate and analyze the conversion of cutting process from physical model to mathematical model.2.Heat,surface roughness,stress and strain is studied during ?-alumina ceramic cutting with single particle diamond.Author dissects 3D simulation of the cutting process and thermal-force coupling by using ANSYS / LS-DYNA.Cracks and topography condition of work surface in different cutting speed is also discussed.In addition,with cutting temperature field fitting into cutting process,cutting heat,the effect of thermal stress towards the tool stress,cutting heat distribution,abrasive stress,work-piece surface topography as well as strain problems during the cutting process are researched.3.A reciprocating diamond wire saw equipment with multi-dimensional cooling equipment has been designed independently which allow automatic precision transmission on YZ direction by using double bearing screw of P2 precision grade.What's more,the guide wheel's tension is adjustable to precisely control the thickness of the work piece so that slice thickness can reach a minimum of 0.5mm.Mitsubishi PLC FX2N-16 MT is used to achieve automatic timing and cooling,wire automatic reversing and feed rate and cutting speed digital control.4.By designing of cooling device with control of diamond wire saw machine,three automated cooling types are realized: air-cooling(20°C),atomized cooling at room temperature(25°C)and 0°C through the use of KR-C water-based cutting fluid.Taking cooling condition as a factor and three cooling methods for reference,orthogonal test is conducted in different wire speed and feed rate to investigate the cooling condition for smallest surface roughness during diamond wire saw cutting.At last,based on the cooling condition,the paper further deliberates the work of wire cutting process parameters optimization,cutter's surface damage reduction,uneven surface thickness,bending and warping defects and other issues.