Date of Award
Master of Science (MS)
A study was conducted to explore the possibility of using machining marks (i.e. surface roughness and lay) as a parameter for die design. The study was performed using 6061-T6 aluminum 1.25" diameter rounds and 0.25" square bar stock to investigate the effects of temperature, surface roughness, and lay on metal flow and friction factor. Metal flow was assessed using component true strains and spread ratio. Compression testing was performed using an instrumented die set that was mounted on a 10 ton hydraulic pres. Cigar tests were performed where the axis of the specimen were oriented at angles of 0o, 45o and 90o with respect to the surface lay on the compression platens. Ring tests were completed to quantify friction factor at different die temperatures and surface roughness values. Results indicate that die temperature has a strong effect on bulge radius and friction factor. Lay and surface roughness were found to exhibit an effect on metal flow but surface lay of the dies was not discernible on friction factor. The study was repeated under limited conditions using graphite lubricant in order to discover if the trend was repeatable using conditions observed in industry. This was found to be the case.