ABSTRACT

This article investigates the effect of ceramic powder bath heat-treatment on the sintering of α-alumina (α-Al₂O₃) for potential ceramic tool application. Three different ceramic sintering mediums were used i.e., (i) Pure alumina powder bath, (ii) Pure graphite powder bath, and (iii) Alumina Graphite Powder Bath (AGPB). The hardness and microstructural analysis were carried out using Vickers hardness, Field Emission Scanning Electron Microscopy (FESEM), and Scanning Electron Microscopy (SEM). The experimental results revealed that the novel Alumina Graphite Powder Bath (AGPB) sintering mechanism proposed in this research provided better hardness and microstructure as compared to the rest. The heating mechanism of alumina and graphite powder mixture was compared with published Thermogravimetric analysis (TGA) results. The Alumina Graphite Powder Bath (AGPB) sintering method improved the mean hardness and relative density by 23% and 13%, respectively. Further, an orderly crystalline corundum microstructure with closed porosity was revealed from Scanning Electron Microscopy (SEM) micrographs. The conversion of convection-radiation to conduction mode of heat transfer in Alumina Graphite Powder Bath (AGPB) sintering technique was the reason behind this property enhancement.

摘要

本文研究了陶瓷粉末浴热处理对α-氧化铝（α-Al ₂ O ₃) 用于潜在的陶瓷工具应用。使用了三种不同的陶瓷烧结介质，即（i）纯氧化铝粉末浴，（ii）纯石墨粉末浴，和（iii）氧化铝石墨粉末浴（AGPB）。使用维氏硬度、场发射扫描电子显微镜 (FESEM) 和扫描电子显微镜 (SEM) 进行硬度和微观结构分析。实验结果表明，与其他方法相比，本研究提出的新型氧化铝石墨粉末浴 (AGPB) 烧结机制提供了更好的硬度和微观结构。将氧化铝和石墨粉末混合物的加热机理与已发表的热重分析 (TGA) 结果进行了比较。氧化铝石墨粉末浴 (AGPB) 烧结方法将平均硬度和相对密度分别提高了 23% 和 13%。更远，扫描电子显微镜 (SEM) 显微照片揭示了具有闭合孔隙的有序结晶刚玉微观结构。在氧化铝石墨粉末浴 (AGPB) 烧结技术中，对流辐射向传导传热模式的转换是这种性能增强的原因。