New zinc-free lubes reveal their strengths

摘要

The aim of using a lubricant during PM compaction is to reduce internal friction between particles and to reduce external friction between the compact and die wall. Zinc stearate and different amide waxes are the most commonly used lubricants. Stearic acid has been used as a lubricant from the beginning, but the problem with stearic acid is that it can give "bad powder" properties and that it easily forms agglomerates both in powder mixes and during storage of the lubricant. Many component manufacturers have problems when using zinc stearate due to stains on sintered components and for environmental reasons.