Accession Number:

ADA250552

Title:

Non-Equilibrium Synthesis by Laser Cladding of Ni, Nb and Mg Alloys for Improved Environmental Resistance

Descriptive Note:

Final rept. Nov 88-Oct 91,

Corporate Author:

ILLINOIS UNIV AT URBANA DEPT OF MECHANICAL AND INDUSTRIAL ENGINEERING

Report Date:

1992-03-30

Pagination or Media Count:

91.0

Abstract:

The technique of laser surface modification provides a unique means of synthesizing novel nonequilibrium materials in near net shape. The goal of the proposed program is to develop a science base for synthesis of nonequilibrium metastable alloys by laser processing. This report summarizes experimental and theoretical studies carried out during the period of November 1988 to October 1991 on laser surface modification of Ni, Nb and Mg alloys for improved environmental resistance at high temperature. A microstructural evolution model of NbA13 was developed and the relative oxidation resistance of claddings of several Nb-based alloys were investigated. Initial work with V revealed that V increases the ductility, and decreases the oxidation resistance of laser clad NbA13. Oxidation behavior of alloys with Ti, B and Hf as a ternary alloy addition were identified Oxidation tests at 800, 1200, and 1400 deg C were conducted on NbA13-0 at B O B, NbA13-0.5 at B 0.5 B, NbA13-1.0 at B 1.0 B, NbA13-1.0 at B-3 at Ti 3 Ti, NbA13-1.0 at B-6 at Ti 6 Ti and NbA13-1.5 at Hf 1.5 Hf alloys. An external layer of x-alumina formed on samples of alloys 0.5 B and 1.0 B isothermally oxidized in air at 800, 1200 and 1400 deg C. A mixture of alumina and NbA104 formed on the samples of alloy 0 B exposed to same testing conditions.

Subject Categories:

  • Physical Chemistry
  • Properties of Metals and Alloys
  • Fabrication Metallurgy
  • Unmanned Spacecraft
  • Manned Spacecraft

Distribution Statement:

APPROVED FOR PUBLIC RELEASE