May 2019 Volume 1

FORGING RESEARCH

Understanding how these topographical features, specifically surface roughness and lay, affect friction and metal flow could allow for improved forging processes and possibly alternate methods in achieving die fill. Kurk, using 6061-T6 aluminum samples, was able to show that die roughness did indeed affect the friction factor and strains in open die forging using the cigar test. He was also able to show that the orientation of the workpiece relative to the surface roughness also influenced the longitudinal strains, transverse strains and spread ratio. He oriented the workpieces at three different orientations, 0˚, 45˚, and 90˚, relative to the surface roughness [11]. By orientating the square bar stock at different orientations, he showed that as the orientation increased angularly, so did the strains and spread ratio. The spread ratio was determined by comparing the true strain in the transverse and longitudinal directions. Kurk’s [11] experiment was done at hot forging temperatures using aluminum workpieces. The next step is to characterize the relationship between die topography and metal flow in warm forging applications. The die topography, surface roughness and lay, will be investigated to determine their individual effects on metal flow. For most metals, temperature also plays

an important role in metal flow and will be controlled to ensure that temperatures are controlled and maintained within the warm forging range are used. Lubrication is also an important aspect in warm forging in regard to controlling friction factor. Without lubrication sticking frictionwill cause diewear and improper test results. FIA members can access the full article by following the link listed below: https://www.forging.org/producers-and-suppliers/ technology/tooling-and-lubrication

FIA MAGAZINE | MAY 2019 44