Experimental Study Of The Powder Forging Rod Fe-base Powder Metallurgy Materials Sintering Characteristics

The paper “Experimental Study of the powder forging rod Fe-base powder metallurgy materials sintering characteristics” is carried out to study the powder forging rod Fe-base powder metallurgy materials sintering characteristics, explore the sintering properties of Fe-based powder metallurgy, to provide experimental and theoretical basis for the actual production of powder forged connecting rod. The sintered powder metallurgy as the object of study, preparation of pure Fe, Fe-C, Fe-Cu, C u-C, Fe-Cu-C mixed powder compacts, etc., select the sintering temperature by using the alloy phase diagram, sintering in the box type resistance furnace, to observe the changes in the microstructure of sintered body by optical microscopy; Scanning electron microscopy was used to the micro composition a nalysis of sintered body; By X ray diffraction test analysis of the formation of phase in the sinter; Analysis of the effects of sintering temperature, holding time on the diameter changes, micro hardness and hardness of the sintered body. The results show that, pure-Fe powder compacts sintered at 1000 ℃, with the holding time, the pores gradually become less, until it disappears. Fe-1C mixed powder compacts sintered at 1100 ℃, optical microstructure consisting of ferrite, granular pearlite; The C element to the Fe diffusion, the formation of a "bright" diffusion reaction zone in the Fe grain boundary,forming a small amount of Fe7C3, C08.0Fe92.1and other compounds. Fe-33 C sintered body diffusion reaction zone is thicker at the Fe/C interface, the formation of Fe3 C, Fe2 0C9, Fe2 C, Fe5C2 and other phases. Fe-Cu mixed powder compacts sintered at 1000 ℃, the optical microstructure from light phase(C u), the dark phase(Fe) component, with the extension of the holding time, the dark phase(Fe) gradually become dispersed, but there is porosity; Fe, C u diffusion of elements, the greater the compaction pressure, the greater the amount of diffusion; The formation of C u9.9Fe1.0, Fe4Cu3 and other phases. C u-33 C mixed powder compacts sintered at 1000 ℃, the optical microstructure from white phase(C u), the black phase(C) component, when sintering at 800 ℃ insulation 20 h, form a relatively regular "flaky" organization; C u-33 C mixed powder compacts after sintering at Cu/C interface diffusion reaction zone is formed, the formation of CuC8 phase. Fe-2Cu-1C mixed powder compacts sintered at 1100 ℃, Optical microstructure consisting of ferrite, eutectoid composition; The addition of C u element, the formation of more pearlite; Liquid Cu filled pores to improve the density of the sintered body and geometric precision; the formation of Fe3 C, Fe2 0C9, Cu9.9Fe1.0, Fe4Cu3 and other phases, to produce the precipitation strengthening and second phase strengthening, improve the micro- hardness of Fe-based; The addition of C u element, reducing the hardness of sintered body, improve the ductility of the powder metallurgy material.