| In this project,new high-temperature erosion wear resistant materials was investigated.Fe-Sialon wear-resisting refractory materials was prepared successfully by the carbon thermal reduction and nitration process(CRN)and high temperature sintering.In addition,we also investigated mechanical property and the high-temperature erosion resistance of Fe-?-Sialon,Fe-Ca-a-Sialon and Fe-Ca-a-Sialon/?-Sialon wear-resisting refractory materials.The experimental results showed that Fe-B-Sialon composite powders was,with carbon addition exceeding 25%,synthesized by CRN at 1450? for 5 hours using fly ash,carbon and iron mineral powders as raw materials.The main crystalline phase of products was ?-Sialon and Fe-Si-Al alloy phase,the micro appearance of B-Sialon presented prism-like growth,and some globular particles around ?-Sialon consisted of Fe,Si and Al elements which was Fe-Si-Al alloy according to XRD and EDS;At 1500? for 5 hours,Fe-Ca-a-Sialon/?-Sialon was prepared by CRN with carbon addition exceeding 50%and 20%iron mineral powders,the main phase of the products was ?-Sialon,Ca-a-Sialon and Fe3Si phase.With carbon addition exceeding 50%and 30%iron mineral powders,Fe-Ca-a-Sialon composite powders was synthesized by CRN at 1500? for 5 hours.The main phase in the products was Ca-a-Sialon and Fe3Si phase.Fe-Sialon composites was also prepared using high alumina coal gangue,iron ore concentrate powders and carbon as raw materials by carbothermal reduction and nitriding reaction.The proper temperature to synthesize Fe-Sialon composites was 1500?,and addition of carbon was theoretical addition and exceeding 10%in this experiment.?-Sialon and Fe3Si was main phase in Fe-Sialon composites,and it showed not very well-developed prismatic crystals,and Fe3Si phase presenting some globular particle around ?-Sialon.The sintering temperature have notable effects on the bending strength of Fe-?-Sialon wear-resisting refractory materials.When iron mineral powders was 10g,with increasing temperature,the bending strength of sample initially increased and then decreased,the apparent porosity of sample initially decreased and then increased;The bending strength and volume density of Fe-Ca-a-Sialon wear-resisting refractory materials first increased and then decreased,with a minimum value of 49.51 Mpa and a maximum value of 89.83 Mpa.The apparent porosity of sample first decreased and then increased;The bending strength and volume density of Fe-Ca-a-Sialon/B-Sialon also initially increased and then decreased,with a minimum value of 66.82 Mpa and a maximum value of 100.69 Mpa.The apparent porosity of sample first decreased and then increased.After experimental research on high-temperature erosion wear resistant of Fe-?-Sialon,Fe-Ca-a-Sialon and Fe-Ca-a-Sialon/?-Sialon wear-resisting refractory materials,the results showed that the quality erosion rate of three wear-resisting refractory materials always decreased with incresing test temperature.When the test temperature was up to 1200?,the quality erosion rate of three wear-resisting refractory materials reached the minimum,which indicated the high-temperature erosion resistance of Fe-?-Sialon,Fe-Ca-a-Sialon and Fe-Ca-a-Sialon/B-Sialon wear-resisting refractory materials was continually improved with incresing the test temperature,and Fe-Ca-a-Sialon'properties was the best of three wear-resisting refractory materials. |
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