Effect of Composite Composition on the Contact Angle of B₄C-xTiB₂/Cu

The wetting behavior of molten Cu on the B₄C-xTiB₂ ceramic composites was investigated in this work. The results show that the contact angle of molten Cu alloy on B₄C-TiB₂ ceramic composites is linear with the composition rate of TiB₂ or B₄C while the temperature is in the range of 1 300 to 1 350 °C, consistent with the expectation of the commonly used theoretical method. However, a nonlinear relationship between the contact angle and the composition rate unexpectedly occurred at temperatures ranging from 1 400 to 1 500 °C. The big difference of the contact angles between the molten metal and the components in the composites was found to be the key point. This result identifies that the commonly used theoretical method only works at a limited difference of the contact angle of the liquid on the different phases in the composites, and fails at a big difference.