Study On Machinability Of Non-magnetic Materials Used In Engine

Non-magnetic materials are widely used in industry, and they play the roles that can not been replaced, especially in power industry and the field of medicine. Moreover, Non-magnetic metals have a great prospect with their excellent mechanical properties and low prices. In developed countries, non-magnetic metals have been used to make engines, and the extent of non-magnetization can reach 95%, but in China, it is still blank in this field.In this paper, the machinability of two kinds of new Mn-Cu non-magnetic cast iron and two kinds of austenite stainless steel is studied, therefore, the research will provide help to further application of non-magnetic material in mechanical devices.The research of machinability about cast irons consists of three respects: the cutting force, the wear of cutting tools and the roughness of surface, in the meantime, the experimental procedures are made by hardness and strength of the material. It can be concluded from the orthogonal experiment of cutting force that the axial thrust force and the radial thrust force are major factors affecting the machinability of 3 cast iron, and the empirical formulas of cutting force are also obtained by curve fitting method. The tool life of carbide-tipped tool is nine and a half minutes while cutting 3 cast iron in cutting-tool-wear experiment, the large component of manganese cause this phenomena. It can be concluded from the cutting-tool-wear experiment and the surface-roughness experiment that the machinability of 2 cast iron is poorer than HT250 and better than 3 cast iron.Then the machinability of 304 and 316 stainless steel is studied from two respects-the roughness of surface and the wear of cutting tools by turning and milling which are always used in the process of engine parts. The results combined with surface topographies show that the surface roughness of 304 and 316 stainless steel can meet the process standards of connecting-rod(Ra0.8~Ra0.4μm) and crankshaft(Ra0.4~Ra0.2μm), but the wear of cutting tools is not good: the tool life of carbide-tipped tool is longer than 30 minutes while cutting 316 stainless steel and is 20 minutes while cutting 304 stainless steel.The experimental data and the process technology of engine parts prove that the non-magnetic materials, which would be used in engine,may entirely take the place of common materials.