Powder Mixes with new lubricants for Part Precision and improve productivity
Powder metallurgy is a cost-efficient process route for the production of net shape or near net shape Components. In many situations, secondary operations for instance, sizing or machining operations are required to meet the tolerance class of the application. Better tolerances of as sintered Components will increase the competitiveness of PM technology by reducing the need for secondary operations. In this presentation, the benefits of advancements in material & mixing methods for dimensional control are discussed. In search of new applications for PM components, the industry has a need for ever higher performing lubricants in metal powder mixes. Over the years, several different paths have been taken to improve performance of mixes. Examples are bonded mixes, mixes for warm compaction and more recently mixes for use with heated tooling. Besides good lubrication during compaction there are several requirements on high performance mixes, such as stable powder behavior in terms of filling the tool, stability to variations in temperature and humidity and environmental friendly. Some newly developed lubricants exhibit improved properties in key areas such as climate robustness, lubrication and the possibility to boost compaction performance by using heated tooling during compaction. Moreover these new lubricants are Zn-free, thus minimizing environmental impact and the need for sintering furnace maintenance. Extensive testing has proven that lubrication is superior to amide wax, lubricant properties are not sensitive to humid climate conditions and that green density can be increased compared to conventional mixes.