1600℃氮气气氛Ti-Al2O3复合耐火材料的相演变行为

Phase Evolution of Ti-AlO Composite Refractory at 1 600 ℃ Nitrogen Atmosphere

以烧结刚玉和金属钛粉为主要原料、酚醛树脂为结合剂制备Ti-Al2O3复合耐火材料样品。将样品置于石墨坩埚中,在碳管炉氮气气氛下1 600℃烧成。对烧后样品的物相演变进行分析,结果表明:钛与氮气反应形成氮化钛,即使金属钛含量达到12%,也能完全氮化;形成的氮化钛多呈片状,也有一定量的晶须状碳氮化钛固溶体存在。氮气气氛中存在的微量一氧化碳气体扩散到样品内部,最终形成稳定的碳氮化钛固溶体。添加3%金属钛的样品中,添加3%石墨粉后样品强度降低约50%。添加或不添加石墨的Ti-Al2O3样品中均形成碳氮化钛固溶体,且碳氮化钛固溶体生成量相近。刚玉样品中出现了Al5O6N,在添加钛的样品中未检测到Al5O6N。添加金属钛的Ti-Al2O3样品中刚玉能稳定存在。建立了Ti-Al2O3样品中相演变的演变机理模型。

Ti-Al2O3 composite samples were prepared using sintered alumina and metallic titanium as the raw materials and phenolic resin as the binder.The samples were placed in a graphite crucible and sintered in a carbon tube furnace at 1 600℃in flowing nitrogen.The phase evolution of the sintered samples was analyzed.The results showed that titanium firstly reacted with nitrogen to form titanium nitride.When the content of titanium reached 12%,it can also be fully nitrided.The titanium nitride formed was mostly a flaky structure,and the rest was whisker-like.A small amount of carbon monoxide in nitrogen atmosphere can diffuse into the sample,and form a stable titanium carbonitride solid solution.For samples with 3%titanium,the strength of the sample with 3%graphite decreased by 50%.Similar titanium carbonitride solid solution was formed in Ti-Al2O3 samples with and without graphite.Al5O6N was found in the corundum sample,but not in Samples with titanium.Alumina can exist stably in the Ti-Al2O3 samples with metal titanium added.The phase evolution mechanism model of Ti-Al2O3 samples was established.