以α-Si₃N₄和β-Si₃N₄粉为原料，采用免烧结工艺在坩埚内壁上分别制备了α-Si₃N₄涂层、β-Si₃N₄涂层以及二者质量比为1 ∶1的复合涂层，然后在这些涂层坩埚中制备得到了多晶硅铸锭，观察了涂层和硅锭的表面形貌，测试了硅锭的表面粗糙度、晶粒大小以及红区长度。结果表明：α-Si₃N₄涂层表面粗糙不平、起伏不均匀，对应硅锭的表面粗糙度和晶粒尺寸最大，红区最长；β-Si₃N₄涂层表面较平整且起伏均匀，对应硅锭的表面粗糙度最小，晶粒尺寸较小，红区最短；复合涂层的表面粗糙度介于上述二者之间，对应硅锭的晶粒尺寸最小，红区长度介于二者之间。

With α-Si₃N₄ and β-Si₃N₄ powders as raw materials, the α-Si₃N₄coating, β-Si₃N₄ coating and composite coating of α-Si₃N₄ and β-Si₃N₄, whose mass ratio was 1:1, were prepared on the inner-wall of crucible by the non-sintering process, respectively, and then the multi-crystalline silicon ingots were obtained in the coated crucible. The surface morphology of the coatings and silicon ingots were observed and the surface roughness, grain size and length of red zone for silicon ingot were measured. The results show that the surface of α-Si₃N₄ coating was rough and undulating unevenly, and the surface roughness and grain size of the corresponding silicon ingot was the largest and the red zone was the longest. The surface of β-Si₃N₄ coating was relatively smooth and undulating evenly; the surface roughness of the corresponding silicon ingot was the smallest, the grain size was relatively small and the red zone was the shortest. The surface roughness degree of composite coating was between those of the above two coatings; the grain size of the corresponding silicon ingot was the smallest and the length of red zone was between the above two silicon ingots.