Study On Technology And Wear Resistance Of WC Particles Reinforced Steel (Iron) Matrix Composites Prepared By Centrifugal Casting

Aimed at the local or integral surfaces of some circular parts bearing loads and high abrasion, ceramic reinforced surface composites have been designed. Forming integrate with composite under the process of centrifugal casting, WC particles reinforced steel (iron) matrix revolving composite materials was successfully prepared.WC particles of 0.190-0.710 mm in size are used as reinforced phase. Bainite/ Martensite cast steel and gray cast iron (HT200) are used as the matrixes. First of all, on the theoretic analysis of the force acted on particles, the particles movement law, the distribution time of particles, the cooling time of mold as well as the casting technique which influence on the techniques of particle-perform infiltration, particle poured together with melt metal and particle precasting process. What's more, by the means of centrifugal casting process, the microstructure of composites made by three different kinds of manufacturing technologies has been systemic observed. Three-body abrasive wear resistance of the composites with matrixes of high-speed steel (W18Cr4V), high-chromium iron (Cr12) and 40Cr have been investigated.By gradient increasing volume fraction of the composite layer, changing the particle size, adjusting the centrifugal casting process in the manufacturing technologies of particle-perform infiltration, Particle selected reinforced steel/iron matrix composites was successfully prepared. However there are some problems in this technology such as complicated process, long production cycle, defects in composite layer and so on. By changing the position which particle entering, taking the advantage of density difference between particle and matrix, adjusting the centrifugal casting process (such as insulation condition of mold,pouring temperature)guided by theoretical calculation, particles gradient reinforced revolving parts was successfully prepared. However there is no force available which is used for uniform distribution WC particles in the axial direction, therefore the manufacturing technology of particle poured together with melt metal was only for preparation revolving parts which are short in the axial direction. For uniform distribution WC particles in the axial direction, improving production efficiency, WC particles reinforced revolving parts which particles uniform distribution in the axial and Radial direction was successfully prepared by changing the way of WC particles adding and designing the powder spreading devices. The particles combined well with each other, without any impurities and cracks, and no massing phenomena between particles. The particles are partly dissolved. The particles and base material are combined with chemical reactions.Under the condition of three-body abrasive wear resistance, the shielding effect of reinforce particles effective protected the matrix for further abrasion. The results of Three-body abrasive wear test reveal that the wear resistant property of composites with three different matrixes is excellent, about 4.6 times as that of high-speed steel (W18Cr4V),6 times as that of high-chromium iron (Cr12) and 11.2 times as that of 40Cr.