Interconnection of high-strength ceramic properties with microstructure and phase composition

The article investigates interconnection of high physical and mechanical characteristics of highstrength building ceramics and phase composition of ceramic shard. The authors identify phase composition and microstructure of clinker brick and porcelain stoneware samples by powder X-ray diffraction and using a scanning electron microscope. The shard structure affects many properties of products, including strength, water absorption, frost resistance, etc. The article considers components of building ceramics microstructure, which give high physical and mechanical characteristics to product. High physical and mechanical properties of clinker bricks are achieved due to the content of needle-shaped mullite. The microstructure of clinker bricks is represented by fused quartz grains and mullite crystals with glass interlayers between them. In porcelain stoneware, fine-crystalline mullite is distributed in the X-ray amorphous phase. Porcelain stoneware has a welldeveloped X-ray amorphous phase due to intensive liquid-phase sintering. In samples of high-strength building ceramics the study establishes leucite crystals formation, having reinforcing effect on structure of a ceramic shard.