β-SiC具有高硬度、耐磨损、抗氧化、机械强度高、高热导率、低线膨胀系数、宽能带隙等一系列优异性能，在航空航天、机械、冶金、电子、军工等领域有着广泛的应用。目前的各种方法虽然都能制备出高纯、超细的β-SiC粉体，但也存在种种弊端，如成本高、产量低、难以产业化。 作者全程参与了课题组发明的无限微热源法合成β-SiC粉体技术的中试研究。经过几十炉次的试验，一次投料量增加到2500kg，并能稳定生产。产率达理论产率的70%，单耗降到了约23Kwh/kg。通过对炉内装料量、电阻和供电功率等变化规律计算、模拟和数值拟合，结合实验研究确定了中试炉的合成工艺参数为：混料时间20分钟、保温功率100Kw、合成时间约130小时、供电制度分四个阶段。 通过X射线衍射仪对产品进行了物相分析，一级品、二级品中主要晶相为β-SiC，在三级品中有杂质石墨相存在；通过扫描电子显微镜对产品进行了形貌观察，主要为无定形或半自形晶体，并有一定程度的团聚；通过激光粒度分析仪进行粒径表征，D95平均在62μm左右，D50平均在25μm左右，通过对产品的化学纯度分析，一次合成的β-SiC粉体纯度达98%以上。 论文探讨了合成中由原料组成的复合粉体的导电机理。认为该复合粉体的电阻是非欧姆性的，宏观上是一个逾渗系统，实验确定的逾渗阈值大约在13%到23%之间。该复合粉体的导电至少存在三种导电机理：主要导电形式是复合粉体系统中相互接触的导电颗粒间形成了导电通道网络集团；其次是相互孤立的导电颗粒或团簇，在热振动的条件下产生隧道效应；再次，存在隧道效应的一种特殊情况，即电场发射机理，在导电颗粒间由于电场的作用产生发射电流。这三种导电形式在不同程度上影响了该复合粉体的非欧姆性。

β-SiC has been extensively applied in aerospace, machinery,metallurgy,electron,military industry,and etc.because of its excellent properties in high hardness,wear resistance,antioxidation,high mechanical strength,high thermal conductivity,small linear expansion coefficient,and wide band gap.At present,although high purity ultrafine β-SiC powders could be prepared by various methods,but there are many disadvantages,such as high cost,low yield and difficult to industrialization. The author participates in pilot-scale research which our team invented synthesis technology of β-SiC powder by infinite-mini-heat source furnace.One-time Charging weight increased to 2500kg ,and β-SiC powder can be stably produced. The yield of β-SiC powder reached 70 percent and unit Consumption reduced to 23Kwh/kg.Through calculation , simulation and numerical fitting the change law of forced filling rate , resistance and power, the main technology parameters determined are as follows: mixing time is 20min, holding power is 100Kw, synthesis time is 130 hours and power supply system is divided into four stages. The results show that main crystal phase is β-SiC in first-grade products and second- grade products，there are graphite impurity in the third-grade products by XRD phase analysis. The appearance of β-SiC powder which was observed by SEM was amorphous or subidiomorphic crystal and had agglomeration to some extent. Characterization result of laser particle size analyzer suggested that average D95 of particle size was about 62μm,and average D50 of particle size was about 25μm. Purity of β-SiC powder product by primary synthesis reached over 98 percent. This paper discusses conductive mechanism of composite powders which consist of different raw materials.The resistance of composite powders is non-ohmic characteristic,and is a percolating systems in macroscale. The percolation threshold which was determined by experiment is from 13 percent to 23 percent.There are mainly three conductive mechanisms on the composite powders. The main conduction mode is that contactile conductive particulates form conducting channel network in composite powders system. Secondly, isolated conductive particulates or clusters produce tunneling effect under the thermal vibration condition.Once again,there is effect of electric field emission which is a special kind of tunneling effect. The production of emission current attribution to effect of electric field in conductive particulates. This three conduction mode affect non-ohmic characteristic of composite powders in different extent.