Accession Number:

AD0625800

Title:

PLASMA-JET COATING OF TUNGSTEN ON STEEL

Descriptive Note:

Final rept. 6 Feb 1961-30 Apr 1962

Corporate Author:

ARIZONA UNIV TUCSON ENGINEERING RESEARCH LABS

Personal Author(s):

• Landingham, Richard L.
• Damon, Robert A.
• Murphy, Daniel J.

Report Date:

1962-04-30

Pagination or Media Count:

138.0

Abstract:

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.

Descriptors:

• *METAL COATINGS
• *STEEL
• *TUNGSTEN
• *PLASMA JETS
• SUBSTRATES
• HEAT TREATMENT
• REFRACTORY COATINGS
• STRESS RELIEVING
• IRON
• SURFACE PROPERTIES
• BONDING
• DIFFUSION
• SPRAYS

Subject Categories:

• Coatings, Colorants and Finishes
• Metallurgy and Metallography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE