Study On Microstructure And Mechanical Properties Of Reverse Polarity Weak Plasma Arc Dissimilar Metal Surfacing

Accompanied the constant development of China's industrial technology and the level of automation, Companies have increasingly recognized the harm caused by the wear failure of parts. As one of materials'main failure mode, abrasion may cause great economical losses to production and living. As result of that, effectively reduce the abrasion and enhancing the mechanical wearing of materials can shows a great economic significance. Surfacing technology often used to improve the wear resistance of materials, as a common surface hardening technology. Because of copper and its alloy is relatively inexpensive price and their good wear resistance, corrosion resistance, electrical conductivity and thermal conductivity characteristics, copper and its alloys are widely used in many fields as a important surfacing material. To further the properties of the base metal, people began to improve surfacing mechanical properties. Grain refinement by magnetic field is a good way to strengthen the surfacing.Aluminum-bronze and copper are melted on 20g and HT200 by using reverse polarity weak plasma arc method with different welding conditions in my papers. External magnetic field was first introduced to the surfacing process of copper alloys. The microstructures of surfacing have been studied by microscope and SEM, hardness, dynamic friction factor and loss weight of the surfacing weld have been measured. A large number of experimental data summarized and analyzed and test results the following conclusions:1)Experiments are summarized in the absence of external transverse magnetic field and the exchange of magnetic field, the optimal welding process parameters of aluminum bronze/20g mild steel, aluminum bronze/HT200 cast iron, copper/20g mild steel, copper/HT200 cast iron can reach the best hardness, wear resistance and the forming; 2) Applied magnetic field can increase the horizontal exchange copper alloy cladding layer hardness and wear resistance, but for different surfacing, there is the best field current, if field current is over, performance will be decreased; 3) By the research on the interface obtained the reasonable welding parameters of reducing the "extra-iron" and found that magnetic field effects on the interface combined with optimization, and can effectively reduce the incidence of defects.