B_6O/TiB_2复合材料的高温高压反应烧结  

Reactive Sintering of B_6O/TiB_2 Composites at High Temperature and High Pressure

作　　者：张瑜[1] 贺端威[1] 王永坤[1] 刘银娟[1] 胡艺[1] 王江华[1] 

机构地区：[1]四川大学原子与分子物理研究所,四川成都610065

出　　处：《高压物理学报》2015年第3期178-184,共7页Chinese Journal of High Pressure Physics

基　　金：国家自然基金(51472171;11427810)

摘　　要：以B和TiO2为初始原料,依据压力可抑制原子长程扩散的动力学效应,通过高温高压(4~5GPa,1 200~1 500℃)一步反应烧结法制备B6O/TiB2复合材料。当B和TiO2物质的量之比为14.0∶0.8时,在5GPa、1 200℃、保温30min条件下得到的烧结样品性能较好,非晶硼(纯度93%~94%)过量混合粉末样品的硬度最高约为29GPa,高纯晶体硼(纯度99.99%)过量混合粉末样品的硬度最高约为32GPa,相对密度可高达99%。实验结果表明:高压抑制晶粒过度长大,同时又有利于B6O的合成,使其合成温度比常压下有所降低;在高压反应烧结过程中,合成的第二相TiB2晶粒和样品中的非晶相有效地消耗了残余应力,起到了增韧作用。B6O/TiB2 composites were produced from B-TiO2 mixtures using 'one step reactive sintering method'at high pressures between 4and 5GPa.The highest Vicker's hardness is 29 GPa for samples consisting of amorphous B and TiO2(molar ratio:14.0∶0.8).For samples consisting of crystal B and TiO2(molar ratio:14.0∶0.8)sintered at the condition of 5GPa and 1 200℃for 30 min,the highest Vicker's hardness is 32 GPa,and the ratio of densification is up to 99%.High pressure restrains the formation of large crystalline grains and promotes the synthesis of B6 O,and reduces the sintering temperature comparing to that at atmospheric pressure.On the other hand,generated additional TiB2 and superfluous boron can improve the fracture toughness of the sintered samples.

关 键 词：超硬材料 高压烧结 硬度 相对密度 增韧机理 

分 类 号：TB332[一般工业技术—材料科学与工程]