ZIRCONIUM DIBORIDE, BORON NITRIDE, AND BORON CARBIDE COMPATIBILITY WITH AUSTENITIC STAINLESS STEEL

The compatibility of zirconium diboride, boron carbide, and boron nitride with type 304 stainless steel was evaluated as a function of temperature (1000 to 12OO deg C), time (1-3 hr). Appropriate loadings of the boron compounds and stainless steel powder were blended and fashioned into a compact powder metallurgically. Each compact was roll clad into a plate and subsequently heat treated at a temperature equal to the initial sintering temperature. Metallographic examination of the fabricated and heat-treated plates demonstrated that none of the systems was metallurgically stable. The instability was generally manifested by the interaction of the discrete boron compounds with the matrix and precipitation of a hypothetically boron-rich phase throughout the stainless steel matrix material. Of the three compounds, boron nitride was relatively the most stable in a stainless steel matrix under the test conditions. (auth