Composition Of Particulate Materials And Process For Obtaining Self-Lubricating Sintered Products

摘要

The metallurgical composition comprises a main particulate metallic material, for example iron or nickel, and at least one alloy element for hardening the main metallic material, which form a structural matrix; a particulate solid lubricant, such as graphite, hexagonal boron nitride or mixture thereof; and a particulate alloy element which is capable of forming, during the sintering of the composition conformed by compaction or by injection molding, a liquid phase, agglomerating the solid lubricant in discrete particles. The composition may comprise an alloy component to stabilize the alpha-iron matrix phase, during the sintering, in order to prevent the graphite solid lubricant from being solubilized in the iron. The invention further refers to the process for obtaining a self-lubricating sintered product.

主权项

1. A metallurgical composition of particulate materials, for forming conformed and sintered self-lubricating composite products, characterized in that it comprises:
a main particulate metallic material, in the form of a main chemical element, wherein the main particulate metallic material is iron, and at least one particulate hardening element, which form a structural matrix in the composite product to be sintered wherein the particulate hardening element has the function of hardening the structural matrix; a non-metallic particulate solid lubricant, at least partially soluble in the structural matrix, wherein the particulate solid lubricant is a mixture consisting of graphite and hexagonal boron nitride; an alloy component, with the function of stabilizing the iron alpha phase and of preventing the solubilization of the particulate solid lubricant in the iron; and at least one particulate alloy element capable of forming, during the sintering of the conformed metallurgical composition, a liquid phase between the main particulate metallic material which forms the structural matrix and the particulate solid lubricant, agglomerating the latter in discrete particles; wherein the particulate solid lubricant represents a volumetric percentage lower than or equal to 15% of the volume of the composite material to be formed and the particulate hardening element, the particulate alloy element and the alloy component are silicon, at contents from 2% to 5% by weight of the metallurgical composition.