From Machining Chips to Raw Material for Powder Metallurgy—A Review

Chips are obtained by subtractive processes such as machining workpieces and until recently considered as waste. However, in recent years they are shown to have great potential as sustainable raw materials for powder technologies. Powder production from metal chips, through the application of solid-state processes, seems to be an alternative to conventional atomization from liquid cooled with different fluids. However, chip material and processing have an essential role in the characteristics of powder particles, such as particle size, shape, size distribution and structure (4S’s), which are essential parameters that must be considered having in mind the powder process and the metallurgy applications. Moreover, different approaches refereed in the application of this new “powder process” are highlighted. The goal is to show how the actual research has been transforming subtractive processes from a contributor of wastes to clean technologies.