The Application Of Fe-N Powder In Preparation Of Fe-Cu-C Powder Metallurgy Materials

Using reduced iron powder as raw material to prepare Fe-N powder by gas nitriding. In this paper, the Fe-Cu-C alloys were obtained by ball milling, compression molding and sintering(pack-carburizing or nitrogen atmosphere) process of Fe-N powder, graphite(0.4%) and copper (4%) mixture. By contrast and analysis of microstmcture, microtopography, component, magnetic properties and corrosion resistance for Fe-N powder, describes the reason to replace reduced iron powder with Fe-N powder to sinter Fe-Cu-C Iron base alloy powder metallurgy material. The microstmctures and compositions of Fe-Cu-C specimens were characterized by metallographic microscope and X-ray diffraction. Comparing the property of Fe(N)-Cu-C material and that Iron base alloy powder metallurgy material under different processing parameters, the density was test by drownproofing, the microhardness were teste by HVS-1000B hardness device, the wearing test for specimens was conducted in a interual M-2000 device.The results showed that the component of Fe-N powder was Fe2-3N, the microstmcture of Fe-N powder were bright substrate and pore, the surface of Fe-N powder distribute lots of honeycomb micropore. Fe-N powder is soft magnetic materials and the saturation magnetization was up to 52.33 emu/g which much less than reduced iron powder. The maximum of corrosion rate was observed during the corrosion experniment, Fe-N powder’s weight gain was only 0.085 times the number for reduced iron powder after 6 hours. Based on denitrifying principle of Fe-N-Cu-C green pressing, Fe-Cu-C alloys were obtained by pack-carburizing or nitrogen atmosphere sintering process. The main component of Fe(N)-Cu-C materials was α-Fe and the microstmcture were blocky ferrite、lamellar pearlite and pore. It was found that the hardness of Fe(N)-Cu-C alloys by pack-carburizing or nitrogen atmosphere sintering process were HV0.05 307.9 and HV0.05 355.4 which was higher than that iron-based material. Under the same condition, the porosity of Fe(N)-Cu-C materials was higher than that iron-based material, Instead, the density value was opposite. To the extent that the pore are contribute to decrease the wear rate. The result shows that in the ring-block sliding wear test, the the mass loss, wear volumeloss, roughness and friction coefficient of Fe(N)-Cu-C materials were less than that iron-based material. Thus, all of the results suggest that Fe(N)-Cu-C material has excellent abrasion resistance.Compared with iron powder, Fe-N powder has its advantages of low cost and good corrosion resistance and can replace iron powder as raw material to produce some iron-base alloy powder metallurgy materials.