Dense SiC Coatings as Barrier Layer on Graphite Heat Elements in Furnaces for Smelting Silicon in Photovoltaic Industry

Abstract

This study puts forward an application of a dense SiC coating of graphite heat elements as a barrier layer to prevent the spoilage of the purity of photovoltaic Si elements by impurities of the graphite. The SiC barrier performance in high‐temperature vacuum environment has been analyzed measuring the mass loss of graphite with/without coating of 5, 20, 30 μm 1200, 1400, and 1600°C. A thickness of 20 μm showed to be the best choice and could reduce the weight loss by more than 90%. The adhesion strength of samples decreased with the increase in heat treatment temperature.

Residual thermal stresses prediction for CVD coating/substrate system based on a numerical model

“…Chemical vapor deposition ceramic coatings, like SiC coating, Si 3 N 4 coating et al, are advanced and promising materials due to their remarkable properties: chemical inertness, high temperature resistance, high stiffness, hardness and toughness, good optical properties, et al Meanwhile the ceramic coating produced by chemical vapor deposition (CVD) as a protection layer has been widely applied in aerospace and semiconductor fields recently. In high temperature, the CVD ceramic coating can effectively prevent oxygen from oxidizing and deteriorating the substrate.…”