Extending die life.

A 10X increase in die life? That is just what Fisher Corp. (Troy, MI) achieved by using a thermal diffusion coating process from Arvin TD Center (Columbus, IN; www.arvintd.com). Fisher stamps small parts for high-volume automakers like GM, so hitting numbers like 50 strokes/min. on its stamping presses is necessary to keep up with just-in-time deliveries. But when it tried to push volumes to that level on complex parts, it found that increased heat in the die combined with restricted material flow caused steel buildup on the tool which eventually gouged it, severely reducing die life. So, Fisher turned to Arvin TD Center which coated the dies using a thermal diffusion process that metallurgically "welds" a layer of vanadium carbide to the die surface. The process is conducted at 1800[degrees]F to create an adhesive bond that is said to be stronger than a deposited coating and not to chip, peel or spall off of the substrate. The resulting die surface has a hardness of approximately 90 Rockwel[l.sub.c], and Fisher found that the coating not only allowed it to meet its strokes/min, requirements, but it gave it a die life of two million hits.