Research Of Ceramics Composite Overlay With Metallic Base

This paper joined the alloy powder of ferro-titanium,ferro-boron,ferro-silicon, high carbon ferro-chrome into the cast-iron base;and adopted plasma arc surfacing to build up the metal alloy powder,including BC,B₄C,CrB,SiC,TiC,Cr₇C₃ etc, making ceramic phase borned automatically.The ceramic phase always is extensively applied inactual production with its high degree of hardness,high resistance to wear, high elastic radio bearing to the high temperature.This experiment combined the better nature of cast-iron base and ceramic phase to integrate fully,producing good toughness,more than HRC61 and good wear resistance hardfacing layer.During the experimental process,this paper systematically studied the effects of welding process parameters to hardness,wear resistance and microstructure of the cladding layer and observed to generate ceramics and the effects of ceramic phase to cladding layer hardness and wear resistance.Experimental process,we systematically studied the welding process parameters on the cladding layer and hardness,wear resistance and microstructure were observed to generate ceramics and ceramic cladding layer relative hardness,wear resistance.The results showed that:(1) a large quantity of ceramic phases were generated in the cladding layer by growned automatically methods,including Cr₂B,TiC,Si₅C₃,Cr₇C₃,B₄C etc.While the amounts of high carbon ferro-chrome,FeB,FeTi,graphite,Ni power and FeSi were controlled within a range of 25-35%,8-12%,15-25%,5-10%,4-6%,2-4%,good wear resistance and above HRC61 hardfacing layer could be obtained.And it had lower cost than adding ceramic phase directly;(2) Appropriate increase C content is in favor of ceramic phase formation;(3) With the increase of welding current, hardfacing layer hardness decreased gradually and a gradual increase in wear volume. In the current 120A,the hardfacing layer hardness is largest and the amount of wear is smallest,what is more,dense microstructure,small grain size and the distribution in the rules,through the second-phase strengthening cladding layer so that the hardness increased;(4) Titanium carbide content in hardfacing layer is less,and it did not transit to weld joint,so it showed that Ti is easy to burn out;but the silicon existed a certain amount in a non-chromium compounds there,it proved that silicon is an easy transition element.