Effect of Yb substitution on microstructure, physical and mechanical properties of negative thermal expansion Zr1−xYbxWMoO8−x/2 (x = 0–0.05) ceramic

Cubic Zr1-xYbxWMoO8-x/2 (x = 0-0.05) ceramic was first fabricated by a polymorphous precursor transition method. X-ray diffraction experiment indicates that samples with x <= 0.05 are single phase solid solution. The measured bulk density, microstructure, maximal compression strength and Young's modulus are obviously sensitive to Yb substitution level, while none of such sensitivity was found for the lattice parameters, negative thermal expansion coefficients and Vickers hardness. Drilling tests on Zr(0.96)yb(0.04)WMoO(7.98) ceramic indicate good machinability, which is often required for quality and shape control in engineering applications. (C) 2008 Elsevier B.V. All rights reserved.