碳化硼的低温热压

研究了B₄C的热压工艺及Al₂O₃对热压B₄C烧结性能的影响。结果表明,采用1.0μm左右的B₄C粉,添加Al₂O₃作为烧结助剂,在1750℃、35MPa热压条件下可获得烧结致密体。而制造纯B₄C材料的热压温度需高于2100℃,才能使坯体致密。添加5%~30%Al₂O₃可明显降低B₄C材料的热压温度,但随Al₂O₃含量的增加,这种作用不很明显,反而使材料的硬度降低。当Al₂O₃含量为5%~10%(Wt)时,材料的硬度(HRA96.5)与纯B₄C热压材料的硬度(HRA97.0)接近。

HOT PRESSING OF BORON CARBIDE AT LOW TEMPERATURE

The present article studied the hot pressing technology of B₄C and the influence of Al₂O₃ on the sintering properties of hot pressed B₄C. It was found that densified sintering product of about 1.0μm B₄C and with addition Al₂O₃ as sintering assistant could be obtained by hot pressing at 1750℃ and 35MPa while hot pressing at over 2100℃ is needed to densify the materials of pure B₄C materials.5%~30% addition of Al₂O₃ can obviously decrease hot pressing temperature of B₄C materials. But such role will not be distinct with the increase of Al₂O₃ contents which will on the contrary decrease the hardness of the materials. In case of Al₂O₃ contents of 5%~10% (wt) the hardness of materials equal HRA 96.5 which is comparatively approximate to the hot pressed pure B₄C materials of HRA 97.0.