A novel design of a high-strength high-temperature graphite die

Graphite die is a critical component in material processing, especially at high temperature. However, its strength is a bottleneck. In this study, we propose a novel, efficient, and economical solution to remarkably enhance the strength of graphite dies by employing the pre-stressed carbon fiber winding technology. An engineering application of a graphite die for hot pressing at 1273 K demonstrated the reliability and practicality: the original graphite die breaks under a punch pressure of 70 MPa and the carbon fiber wound graphite dies work well under a punch pressure up to 100 MPa. The finite element simulations illustrate that the 1-mm-thick layer of carbon fiber is able to reduce the maximum principal stress of the graphite die effectively from 130 MPa to 30 MPa. This is the first application of the pre-stressed carbon fiber winding technique to high-temperature components.