Spark Plasma Sintering Using Shuri Castle Breakage Roof Tile Powder

Abstract

This report investigated the spark plasma sintering (SPS) of Shuri castle breakage roof tile powder for the effective utilization of the Shuri castle breakage roof tiles. First, we examined the fundamental characteristics of Shuri castle breakage roof tiles. The chemical composition of broken roof tiles mainly comprises SiO 2 . Scanning electron microscopy analysis revealed the dispersion of quartz lumps in the inner structure. Additionally, the density of the broken roof tile was 2.43 g/cm 3 , and the open porosity was 17.9%, the Vickers hardness (HV) was 87.5 at the matrix side and 1200 at the quartz lump, and the flexural strength was 15.7 MPa. Meanwhile, the fundamental characteristics of the SPS compact formed using breakage roof tile powder comprised a density of 2.68 g/cm 3 , an open porosity of approximately 0%, an HV of 259, a flexural strength of 105 MPa, and a flexural modulus of 83.1 GPa at a sintering temperature of 1323 K. The formation of magnetite was confirmed via X-ray diffraction patterns of the sintered products; however, the crystalline phases were almost identical to those of the broken roof tile powders.