Effects Of Pretreatment On Microstructure And Properties Of WC_p Reinforced Fe-based Composites By Arc Reaction Synthesis

The traditional wear-resistant materials are difficult to meet modern industryperformance requirement while the WCp reinforced iron matrix composite coatingmaterial is an effective way to solve this problem.As the existence ofdecomposition,pollution and high-cost when adding WC directly,it is a new choice toadopt the way of powder reactive synthesis by tungsten powder and graphite.However,raw material uniformity should be considered in the in-situ reactionsynthesis, lightweight graphite can lead to uneven mixing phenomenon. So thetungsten powder and graphite as raw material,supplemented by tracesilicon,aluminum and magnesium powder and so on arc stability deoxidizer,afterpre-sintering in the vacuum,made of prefabricated coating in the surface of steel,WCparticle reinforced iron matrix coating material was synthesized via arc. This articlestudied the influence of raw materials and the coating of the structure andperformance in raw materials pretreatment.Uniformity,microstructure and properties of the coating.Raw material forsintering processing helps to improve the uniformity,achieve the goal of "carbonsequestration",and choose the appropriate technology for raw materials in theprocess of presintering W,C element diffusion. In this paper, analyzing the influenceof raw materials in the forming method of raw material, presintering temperature andraw material mole ratio, W, C atoms in showed that when pressing pressure280MPa,briquetting have good appearance molding and high density; with the improvementof pre-sintering temperature, W2C and WC gradually appeared in pre-sinteringbriquetting, W-C atom’s bonding strength enhancement; W, C combined with highstrength; W: C (mole ratio of atoms)=1:1.5than W: C (mole ratio of atoms)=1:2overall particles has good uniformity.Raw material by different process, the preparation of phase in the coatingwithout change, but the hard phase volume fraction and evenness have biggerdifference, which affect the hardness and the wear resistance of the coating. Themicrostructure of the coating was composed of WC, Fe3W3C, M7C3and martensite.Raw materials for different forming method of WC hard phase in the coatinghas a great influence on the distribution uniformity, briquetting way hsa betteruniform than apparent way in microstructure, preparation of the coating hardness gradient distribution more reasonable, wear-resisting performance is better, therelative wear resistance is14times as much as matrix. Raw materials by differentpresintering temperature in the preparation of the coating, with the improvement ofpre-sintering temperature, the volume fraction of WC in the coating increases, theuniformity of microstructure is significantly improved, hardness and wear resistanceincrease and friction coefficient reduce. Select different W, C atoms than the rawmaterial for sintering process, the preparation of the coating, when W: C (mole ratioof atoms)=1:1.5, coating microstructure even, WC particle size of hard phase isbigger, good wear resistance; When W: C (mole ratio of atoms)=1:2, because ofmore crystallization crack in coating makes the abrasion resistance is poor.