Strength Testing of Ultrafine WC-6 Co Hard Metal Produced by Spark Plasma Sintering Using the Ball on Three Balls Test

摘要

The biaxial ball on three balls test (B3B test) is a relatively new strength testing method for ceramic materials. A disc shaped sample is centrically positioned on three balls and is loaded by an additional ball on the upper side of the sample until failure. The highest tensile stress occurs in the center of the sample. As a result the B3B test is not sensitive to concave or convex sample geometry and also to the flatness and roughness of the samples in comparison to uniaxial or biaxial bending tests. In the present study the B3B test was used for strength measuring on disc shaped samples of ultrafine WC-6 Co, which were consolidated by Spark Plasma Sintering. The paper will discuss the applicability of the B3B test for measuring the strength of cemented carbides.