The dense TiC Fe cermets were produced by self propagating high temperature synthesis and pseudo hot isostatic pressing(SHS/PHIP). The influence of Fe content on the combustion temperature, combustion velocity, densit...The dense TiC Fe cermets were produced by self propagating high temperature synthesis and pseudo hot isostatic pressing(SHS/PHIP). The influence of Fe content on the combustion temperature, combustion velocity, density and microstructure of products was studied. The composition and microstructure of the product were analyzed. The results showed that the cermet consists of quasi spherical TiC particles and Fe binder phases. A thin diffusion layer was found between Fe binder phase and TiC particle. In the range of 10%～20% Fe content, the combustion temperature and velocity decrease more slowly than the other contributions.展开更多
This work reports research concerning the microstructure and sliding wear behaviour of cermet coatings deposited by high velocity oxy-fuel (HVOF) spraying. Two cermets were prepared with the following target compositi...This work reports research concerning the microstructure and sliding wear behaviour of cermet coatings deposited by high velocity oxy-fuel (HVOF) spraying. Two cermets were prepared with the following target compositions namely, Ni (Cr)-65 wt.% TiB2 and Ni (Cr)-40 wt.% TiB2. Coating microstructures were investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD), whilst microhardness and sliding wear tests were performed on the coatings to evaluate their performance. The HVOF sprayed deposits had layered, splat-like morphologies typical of thermally sprayed cermets. Coatings consisted primarily of TiB2 particles in a nickel-based binder phase. Other minor peaks in the XRD patterns belong to TiB, Ni2B, NiTiO3 and Ti2Oj. The coatings exhibit an amorphous halo in the diffraction pattern between 2 values of 40° and 50°. Sliding wear behaviour was examined using a conventional ball-on-disc apparatus. A sintered ceramic ball (A12O3) was employed as the counterface. The Ni (Cr)-65 wt.% TiB2 coating had a lower wear rate than Ni (Cr)-40 wt.% TiB2 coating. This may be related to the larger sizes of borides. Wear scar morphologies, on both coatings were examined by using SEM and EDAX detecting in order to establish the wear mechanism. Wear is proposed to proceed by subsurface cracking in these coatings.展开更多
文摘The dense TiC Fe cermets were produced by self propagating high temperature synthesis and pseudo hot isostatic pressing(SHS/PHIP). The influence of Fe content on the combustion temperature, combustion velocity, density and microstructure of products was studied. The composition and microstructure of the product were analyzed. The results showed that the cermet consists of quasi spherical TiC particles and Fe binder phases. A thin diffusion layer was found between Fe binder phase and TiC particle. In the range of 10%～20% Fe content, the combustion temperature and velocity decrease more slowly than the other contributions.
文摘This work reports research concerning the microstructure and sliding wear behaviour of cermet coatings deposited by high velocity oxy-fuel (HVOF) spraying. Two cermets were prepared with the following target compositions namely, Ni (Cr)-65 wt.% TiB2 and Ni (Cr)-40 wt.% TiB2. Coating microstructures were investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD), whilst microhardness and sliding wear tests were performed on the coatings to evaluate their performance. The HVOF sprayed deposits had layered, splat-like morphologies typical of thermally sprayed cermets. Coatings consisted primarily of TiB2 particles in a nickel-based binder phase. Other minor peaks in the XRD patterns belong to TiB, Ni2B, NiTiO3 and Ti2Oj. The coatings exhibit an amorphous halo in the diffraction pattern between 2 values of 40° and 50°. Sliding wear behaviour was examined using a conventional ball-on-disc apparatus. A sintered ceramic ball (A12O3) was employed as the counterface. The Ni (Cr)-65 wt.% TiB2 coating had a lower wear rate than Ni (Cr)-40 wt.% TiB2 coating. This may be related to the larger sizes of borides. Wear scar morphologies, on both coatings were examined by using SEM and EDAX detecting in order to establish the wear mechanism. Wear is proposed to proceed by subsurface cracking in these coatings.
