首先,以煤矸石基β-SiAlON粉(以煤矸石和炭黑为原料,采用碳热还原氮化法合成)、硅粉、铝粉和α-Al2O3微粉为原料,采用二次氮化法制备了β-SiAlON材料,研究了原料配比、合成温度以及煤矸石基β-SiAlON粉纯度对β-SiAlON材料性能的影响。然后,选择二次氮化制备β-SiAlON材料的合适工艺参数,分别以不同量(质量分数分别为30%、50%和70%)SiC取代煤矸石基β-SiAlON粉,制备了不同复合比例的β-SiAlON-SiC材料。结果表明:(1)在二次氮化制备β-SiAlON材料时,增加Si粉、Al粉和α-Al2O3微粉加入量以及提高合成温度均有利于提高β-SiAlON的常温抗折强度和体积密度,降低其显气孔率;采用未除杂的煤矸石基β-SiAlON粉有利于β-SiAlON的强度。(2)在制备β-SiAlON-SiC复合材料时,SiC的最佳加入量(质量分数)为50%。
β-SiAlON was synthesized by secondary nitridation method with starting materials of coal gangue based β-SiAlON powder(prepared from coal gangue and carbon black by carbothermal reduction nitridation method),Si powder,Al powder,and α-Al2O3 micro powder.Influence parameters such as formulations of starting materials,synthesis temperature,and purity of coal gangue based β-SiAlON powder were investigated.Then β-SiAlON-SiC composites were prepared by substituting coal gangue based β-SiAlON powder with SiC powder in different mass proportions(30%,50%,and 70%)based on the optimum technique parameters of β-SiAlON preparation.The results show that:(1)with the increases of Si powder addition,Al powder addition,α-Al2O3 micro powder addition,and the rising temperature,cold modulus of rupture and bulk density of the prepared β-SiAlON increase,and apparent porosity decreases;and adoption of the primary coal gangue based β-SiAlON powder is beneficial to strength of prepared β-SiAlON;(2)the optimum SiC addition of β-SiAlON-SiC composites is 50%(mass percent).