Specific interface prepared by the SPS of chemically treated Mg-based powder

This work focuses on a new way of preparation of magnesium-based composite materials by powder metallurgy. This method consists of combination of chemical treatment of magnesium powder in hydrofluoric acid and subsequent compaction by spark plasma sintering. As a result a continuous network of magnesium fluoride coating is created inside material. However, magnesium alloys behave differently in hydrofluoric acid. In the case of WE43 alloy a network consisting of magnesium fluoride and newly emerged yttrium fluoride is prepared. This specific interface of the prepared composite material resulted in a corrosion rate that was three times lower compared to that of the sample sintered without chemical treatment. The cause of improvement of corrosion properties is illustratively shown on the cuts of the samples after immersion. The corrosion front is slowed down on the fluoride interface. The presence of yttrium fluoride phases on the interface slightly reduced mechanical properties.