Milling of magnesium powders without additives

Mechanical milling of ductile metals and alloys into fine powders is difficult to achieve due to particle agglomeration. Even though cryogenic milling and/or wet milling can lead to substantial reduction of particle size, the production of fine powders from ductile metals and alloys is a difficult process. The current study deals with the milling of Mg and examines alternative processing methods that would yield an efficient size reduction. Two methods were studied; milling with MgH2 addition, and milling the powders pre-deformed by equal channel angular pressing (ECAP). The study showed that both methods are successful in preventing particle agglomeration resulting in a significant reduction in particle size. Equal channel angular pressing has the advantage that could be applied to all metals and alloys whereas milling with hydride could only be applied to metals forming their own hydride. It is concluded that, of the two methods, milling with hydride addition is a more effective method of size reduction.

Three microstructures given in the GA refer to "Mg milled", "Mg ECAPed and milled" and "Mg milled with MgH2" in respective order.Figure optionsDownload as PowerPoint slideHighlights
► Comminution of Mg powders was investigated with dry milling.
► Two methods were used; pre-deformation by ECAP and milling with MgH2 addition.
► Both methods are successful in preventing particle agglomeration.
► Milling with MgH2 addition is a more effective method of size reduction.