BIMODAL AND MULTIMODAL DENSE BORIDE CERMETS WITH SUPERIOR EROSION PERFORMANCE

摘要

Multimodal cermet compositions comprising a multimodal grit distribution of the ceramic phase and method of making are provided by the present invention. The multimodal cermet compositions include a) a ceramic phase and b) a metal binder phase, wherein the ceramic phase is a metal boride with a multimodal distribution of particles, wherein at least one metal is selected from the group consisting of Group IV, Group V, Group VI elements of the Long Form of The Periodic Table of Elements and mixtures thereof, and wherein the metal binder phase comprises at least one first element selected from the group consisting of Fe, Ni, Co, Mn and mixtures thereof, and at least second element selected from the group consisting of Cr, Al, Si and Y, and Ti. The method of making multimodal boride cermets includes the steps of mixing multimodal ceramic phase particles and metal phase particles, milling the ceramic and metal phase particles, uniaxially and optionally isostatically pressing the particles, liquid phase sintering of the compressed mixture at elevated temperatures, and finally cooling the multimodal cermet composition. Advantages disclosed by the multimodal cermets are high packing density of the ceramic phase, high fracture toughness and improved erosion resistance at high temperatures up to 1000° C. The disclosed multimodal cermets are suitable in high temperature erosion/corrosion applications in various chemical and petroleum environments.