DID YOU KNOW? DTIC has over 3.5 million final reports on DoD funded research, development, test, and evaluation activities available to our registered users. Click HERE
to register or log in.
PLASMA-JET COATING OF TUNGSTEN ON STEEL
Final rept. 6 Feb 1961-30 Apr 1962
ARIZONA UNIV TUCSON ENGINEERING RESEARCH LABS
Pagination or Media Count:
Three methods for bonding plasma-jet sprayed tungsten to steel were developed and evaluated in an approach to the problem of providing heat- resistant materials for the design and fabrication of components for high temperature applications. Three types of coating were sprayed by plasma-jet on 1020 steel substrates 1 an all tungsten coating, 2 a coating graded from 1020 steel at the interface to tungsten at the outer surface, and 3 a coating graded from iron at the interface to tungsten at the outer surface. By the latter two coating methods, a less severe thermal expansion gradient was developed between the substrate and the coating. Pre-heating the substrates increased the fusion bond at the interface. Post-heat treatments eliminated residual stresses within the coating and promoted grain growth and diffusion across the fusion zone. The tungsten-iron graded coating on the 1020 steel substrate displayed excellent resistance to shock and withstood high temperature corrosion conditions 2 12 times longer than uncoated substrates. The investigation emphasized the potential of the plasma-jet gun in providing a means for depositing a protective coating on a metallic substrate.
APPROVED FOR PUBLIC RELEASE