IMPROVED ELEVATED TEMPERATURE STRENGTH OF ALUMINUM BASED ALLOYS BY THE ADDITION OF RARE EARTH ELEMENTS

摘要

A rapidly solidified aluminum based alloy consists essentially of the formula AlbalFeaMbSicRd, wherein M is at least one element selected from the group consisting of V, Mo, Cr, Mn, Nb, Ta, and W; R is at least one element selected from the group consisting of La, Ce, Pr, Nd, Sm, Gd, Dy, Er, Yb, and Y; ''a'' ranges from 3.0 to 7.1 atom %; ''b'' ranges from 0.25 to 1.25 atom %; ''c'' ranges from 1.0 to 3.0 atom %; ''d'' ranges from 0.02 to 0.3 atom % and the balance is aluminum plus incidental impurities, with the provisos that (i) the ratio [Fe+M]:Si ranges from about 2.0:1 to 5.0:1 and (ii) the ratio Fe:M ranges from about 16:1 to 5:1. The alloy exhibits improved elevated temperature strength due to the rare earth element additions without an increase in the volume fraction of dispersed intermetallic phase precipitates therein. This enhancement of elevated temperature strength makes the alloys of the invention especially suited for use in high temperature structural applications such as gas turbine engines, missiles, airframes and landing wheels.