HEAT TRANSFER BETWEEN SOLIDS
Abstract
In attempts to improve thermal performance of modules for thermoelectric generators an investigation based upon a program of experimentation in thermal conductance between plane solid surfaces in both dry and lubricated contact under pressure was conducted. Surface materials were Type 6061-T6 aluminum alloy and Type RS-70 unalloyed titanium. In some tests a 0. 0027-inch mica layer was interposed between the metallic surfaces, with dry contact. Values of conductance were determined over a range of imposed pressures between 5 and 225 pounds per square inch (psi) in most cases, otherwise at a single pressure of approximately 100 psi. Disparate results led to the conclusion that conductance may be related to the hardness as well as the roughness of the contacting surfaces. Curves of conductance versus imposed pressure usually have a point of inflection at which they change from convex to concave upward, with the rising pressure. It was established that the higher the value of surface roughness, the lower the pressure at which the point of inflection occurs. A lubricated-contact aluminum/aluminum joint showed a conductance at 100 psi, approximately six times the dry-contact value. A dry- contact joint with the specified mica layer interposed showed a conductance approximately 1/6 the original metal-to-metal value. Results for a variety of surface material combinations are presented in a tabulation arranged for comparative study.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1965
- Accession Number
- AD0467809
Entities
People
- Robert P. Kolb