Diversification of PTCR properties by processing

The positive temperature coefficient of resistance (PTCR) property of Pb-containing barium titanate ceramics is liable to change because of processing. The influences of processing conditions, such as ball substance, ball-milling time, calcination and sintering conditions, and setters used in sintering, were studied. Processing criteria to get a high reproducibility and controllable PTCR properties are suggested. An adequate processing technique for PTCR preparation, including agate or polyurethane-coating iron ball-milling and a stable setter in sintering, was evaluated by exploring the influences of calcining and sintering conditions. It was concluded that a uniform microstructure with smaller grain size always results in a better PTCR property