Defects in undeformed, annealed single crystals and in deformed single crystals of WC were characterized by means of transmission electron microscopy. Deformation was produced by indentation with a microhardness tester. High densities of stacking faults with atomic displacement vectors of 1/6<11•3> were found to be lying on {11•0} planes near to the indentations. Stacking faults with displacement vectors of 1/6<11•3> and undissociated dislocations with b = <00•1>, 1/3<11•0> and 1/3<11•3> were observed at distances greater than 2μm from an indentation. The Burgers vectors of the partial dislocations bounding one fault were found to be identical, 1/6<11•¯3>, resulting in a total Burgers vector for the extended dislocation of b = 1/3<11•¯3>, with a stacking-fault energy of 55mJ/m2). Stacking faults with a displacement vector of 1/6<11•¯3> were described in terms of the crystal structure of WC. It was found that the coordination of carbon atoms by tungsten atoms was preserved at the fault, that the number of bonds per atom which were broken during slip could be minimized and that the 1/6<11•¯3> type of partial Burgers vector could be combined to form several types of total Burgers vector.

Room-Temperature Deformation Mechanisms and the Defect Structure of Tungsten Carbide. M.K.Hibbs, R.Sinclair: Acta Metallurgica, 1981, 29[9], 1645-54