Research On The Preparation Of Wear Resistant Material On Picks

Currently, the wear-resistant materials of picks are coarse-grained WC carbide. Carbide has a special corrosion resistance, high hardness, excellent fracture toughness and compre-ssion strength, called modern industrial teeth. The most widely use of the cemented carbide is WC carbide. In the traditional process, the production of cemented carbide picks is sintered by the WC and cobalt, but that process is complicated.Different from the traditional process, this paper proposes using the plasma situ metallurgical technology preparation of the wear-resistant block materials in the blind hole of picks. This is a new method of preparation of making wear-resistant materials. There are three advantages of this new method. Firstly, low cost, raw materials are W or WO3 powder and carbon powder. Secondly, short process, replacing the complexity of powder metallurgy technology, wear-resistant materials directly generated in the picks block. Thirdly, achieve metallurgical bonding, avoiding the problems caused by brazing carbide.In this paper, it is proved that in the WC by the preparation of the feasibility of WO3 in ultra-high temperatures by using the second law of thermodynamics. When more than 1000K, C and WO3 may be solid-solid reaction, liquid-liquid reaction, iron bath reaction, liquid-liquid reactions, and all of those are endothermic reactions, as the temperature increased, the positive reactions were favorable, but WO3 trial in the experiment of the block by the wear-resistant materials, cracks are more poor shape, did not achieve the expected results.The density of wear-resistant materials bulk prepared by the W is better, WC grains are randomly distributed aggregation, the maximum hardness is more than 1987HV, WC crystal grain size is generated by the way of step-phase growth; addition to WC grain size, there are M6C (Fe3W3C-Fe4W2C),Cr7C3, (Fe,Cr,Ni)3C and y-Fe in the wear-resistant materials in the bulk phase. M6C in which wear-resistant materials is the main hard phase, the overall average micro hardness is 1254HV, the block contains a lot of wear-resistant just like the W elements, significantly increases the resistance of corrosion and wear ability; Formed by W, Cr, Fe which as the main hard phase dispersed points distributed in the picks body, the carbides play a good supporting role on the WC phase, to achieve a high hardness and wear resistance. Wear-resistant materials were tested and analyzed on the composition, microstruture, properties, the results showed that, wear-resistant materials prepared by the W hardness, wear resistance initially meet the target, and has good mechanical properties of strength and toughness. This method has the advantage of the process and cost, it will certainly have a great prospect in picks manufacturing.