Powder composition for the manufacture of casting inserts, casting insert and method of obtaining local composite zones in castings

摘要

A powder composition is used for the fabrication of casting inserts designed to produce local composite zones resistant to abrasive wear. The composite zones are reinforced with carbides and borides or with mixtures thereof formed in situ in castings. The powder includes powder reactants of the formation of carbides and/or borides selected from the group of TiC, WC, ZrC, NbC, TaC, TiB2, ZrB2, or mixtures thereof. The carbides and/or borides forming after crystallization particles reinforces the composite zones in castings. The powder composition further includes moderator powders in the form of a mixture of metal powders, which after crystallization form matrix of the composite zone in casting. A casting insert is disclosed for the fabrication in casting of local composite zones resistant to abrasive wear. A method for the fabrication of local composite zones in castings uses for this purpose the reaction of the self-propagating high temperature synthesis (SHS).