Article having cast metal portion and sintered metallic portion and method of producing same

摘要

An article comprising a first portion which is formed porously by sintering of an alloy or cermet material and a second portion which is formed of a metal and intimately bonds to the first portion. For example, the article is a rocker arm for an automotive internal combustion engine, in which first portion is the wear-resistant tip portion and the second portion the body portion. The second portion is formed by molten metal forging, with the sintered first portion set in the mould as an insert, such that the molten metal under pressure is forced to infiltrate into the pores of the sintered first portion at least in a region contiguous to the interface between the first and second portions. This article features very high strength of the bond at the interface between the first and second portions.