Abstract: A debarking knife includes a plate having at least one sharp debarking edge delimited by a leading face and a trailing face. The leading face is reinforced by an anti-abrasion hard surface coating having better anti-abrasion qualities than the substrate forming the plate. The anti-abrasion hard surface coating is preferably a mixture of grains of fused tungsten carbide bound by an Ni/Cr/B/Si alloy, the whole being brazed to the substrate using a laser beam.

Abstract: A paper pulp defibering or refining plate in accordance with the invention comprises a comminuting surface having a large number of ridges separated by grooves. The plate body is made from a first material such as stainless steel or cast iron providing the overall mechanical strength of the plate in use. The upper part of the ridges is a layer of an abrasion resistant material based on grains of tungsten carbide bound in a metal alloy whose melting and brazing characteristics are appropriate to laser resurfacing on the plate body. The ridges are resurfaced successively by scanning a laser beam and a powder spray nozzle in one or more passes.

Abstract: A paper pulp defibering or refining plate in accordance with the invention comprises a comminuting surface having a large number of ridges separated by grooves. The plate body is made from a first material such as stainless steel or cast iron providing the overall mechanical strength of the plate in use. The upper part of the ridges is a layer of an abrasion resistant material based on grains of tungsten carbide bound in a metal alloy whose melting and brazing characteristics are appropriate to laser resurfacing on the plate body. The ridges are resurfaced successively by scanning a laser beam and a powder spray nozzle in one or more passes.

Abstract: An excavating tool tooth includes a mounting area (10) and a working area (11). The working area (11) includes longitudinal bars (14-18) made of a hard material. The bars are inserted in the steel and snugly contact the tooth's cutting face. The presence of the rods made of a hard material substantially increases the tooth's service life. The bars are produced by infiltration.

Abstract: The process according to the invention involves using an infiltration technique with a binder metal 16 in a layer filled with grains of melted tungsten carbide 15, the layer being arranged between the walls of a mould 13 and a core 2, the walls of the mould being made of foundry sand bonded by resins. The invention makes it possible to reduce the cost of the infiltration process.

Abstract: The present invention relates to the manufacture of abrasion-proof plates. The abrasion-proof surface of the plate is composed of external face 5 of a layer of composite material based on spherical grains of melted tungsten carbide bonded in a soldering alloy. Grinding surface 5 has a smooth and even mould finish. The abrasion-proof layer contains a compact, regular and essentially uniform random distribution of tungsten carbide grains. Surface 5 is made by moulding: the tungsten carbide grains are inserted between the mould walls and core 2 of the part, and the soldering alloy is made to infiltrate between the powder grains, core 2 and the mould by increasing the temperature. The invention allows a significant increase in the abrasion resistance of grinding plates.

Abstract: A method and device are provided for producing refractory materials by induction, in which process a mixture of material powders and a binder in solution in water are compacted by extrusion so as to form a solid bar. The bar is introduced into a cold crucible and is caused to melt by magnetic induction. The molten material flows through a lower orifice of the crucible. The invention applies more particularly to the melting of tungsten carbide.