STUDY OF VACUUM WELDING.
Final rept. 2 Mar 64-1 Jan 66,
NATIONAL RESEARCH CORP CAMBRIDGE MA NORTON EXPLORATORY RESEARCH DIV
Pagination or Media Count:
Vacuum cold welding and shear friction of several engineering materials was studied at extremely high vacuum levels above 10 to the -12th power torr in the temperature range 90 to 260 C with interface contact stresses up to 1000 psi. The effect of surface finish and the effectiveness of antiadhesion coatings including Al2O3, ZrO2, Cr2O3 and MoS2 were examined under the same conditions. The residual adhesion force was generally found to vary inversely with hardness or yield strength for each material and to increase with temperature. Increasing the smoothness of the contact surfaces tended to increase the residual or zero-load bonding force as well as to decrease the frictional shearing force under load. The most effective antiadhesion coating observed was MoS2 which substantially prevented welding under the most severe environmental conditions tested.
- Manufacturing and Industrial Engineering and Control of Production Systems