Extruded Al–Al2O3 composites formed in situ during consolidation of ultrafine Al powders: Effect of the powder surface area

Microstructure and mechanical properties of extruded profiles made from pure magnesium powders

“…Figure 3b shows representative tensile stress-strain curves for Mg materials. As illustrated, the stress-strain curve exhibits continuous strain hardening, which is typical for the extruded material from powders reported previously by Balog et al [25] on Al powders. The typical value of ultimate tensile strength (UTS) of WE43 PM is ∼ 310 MPa with uniform elongation of about 4 %.…”

“…Also, in the case of studied Mg PM, the mechanical properties can be related to grain size and grain boundaries strengthening, which is improved by the native oxide layer along with the original powders prior extrusion. Since this layer is compact after extrusion its increment to increase of the UTS is significant [25]. From the above mentioned, it could be concluded that the Mg PM material is a good candidate for the biocompatible and biodegradable material since the mechanical properties are significantly improved and approach WE43 values.…”

“…MgO is a native oxide layer formed on the Mg surface as a result of the high affinity of Mg to oxygen immediately as the surface is exposed to air [24]. This native oxide layer should act as a barrier to dislocation motion during mechanical straining thus should improve mechanical properties of the profiles as in case of Al-based PM material made through direct extrusion as published by Balog et al [25]. Moreover, based on literature [26,27], such native envelope could act as a barrier to corrosion and improve biodegradable properties of Mg as in case of surface-treated powders WE43 with HF [28].…”

Microstructural and Mechanical Properties of Al‐Based Composites Reinforced with In‐Situ and Ex‐Situ Al2O3 Nanoparticles

“…[32] Moreover, it has been reported that the Al powder is covered by a very thin layer of native oxide, whose thickness was estimated to be lower than 4 nm at room temperature and in the amorphous phase. [23][24][25][26][27] Therefore, it is reasonable to assume that also this layer was fragmented by the ball milling processing and that the resulting alumina debris were embedded into the metal matrix.…”

“…According to previous works, the thickness of this layer formed at room temperature is lower than 4 nm. [23][24][25][26][27] The nominal oxygen content in the Al powder was lower than 0.5 wt% according to data supplied by the producer. The alumina suspension in isopropyl alcohol was supplied by Sigma-Aldrich.…”