Precipitation behavior of an ultra-fine grained Mg–Zn alloy processed by high-pressure torsion

Characterization of Powder Metallurgy Processed Pure Magnesium Materials for Biomedical Applications

“…Increasing the compaction pressure (above 300 MPa) at RT had an influence on the deformation of the powder particles while increased deformability of particles corresponded with increasing compaction pressure. The influence was also sufficient for changing the character of the porosity from open porosity to closed porosity and decreased the number of pores on the samples' cross-sections, which is in agreement with [11][12][13]. Hot pressing led to a significant decrease of the porosity of the compacts and also to a change in the character of the porosity (Figure 2) [4,32].…”

“…Powder particles' deformation leads to cracking of the layer of corrosion products normally present on the powder particles' surface [11][12][13]. The applied plastic deformation results in an increase of the contact area of powder particles and, in combination with the applied temperature, enhances the diffusion processes.…”

“…The applied plastic deformation results in an increase of the contact area of powder particles and, in combination with the applied temperature, enhances the diffusion processes. Increasing compacting pressures usually also lead to a decrease in the porosity of the processed bulk material [11][12][13]. The porosity of the processed bulk material is usually considered as a disadvantage of the PM processing techniques.…”

“…Conversion coatings are widely studied as corrosion protection for magnesium and its alloys. Fluoride and calcium phosphate-based conversion coatings have a great potential of reducing the corrosion rate of biomedical magnesium implants [1][2][3][4][12][13][14][15][16][17][18][19][20][21][22][23][24].…”

On the use of cryomilling and spark plasma sintering to achieve high strength in a magnesium alloy

“…Razavia et al [15] reported that the grain size of AZ31 produced by ECAP could be reduced to 350 nm, giving an alloy with a yield strength of 385 MPa and ultimate tensile strength of 455 MPa with 13% ductility, which is the highest reported combined strength and ductility for an AZ31 alloy. Meng, Lu, Trividy and co-authors [19][20][21] found that an ultrafine-grained or nanocrystalline microstructure could be obtained in precipitate-hardened magnesium alloys via severe plastic deformation processes due to the combined high deformation and significant pinning effect from precipitates. With addition of 0.46% CaO, the strength of ultrafine-grained AZ31-CaO produced by 6 passes of equal channel angular pressing was enhanced without the loss of ductility [22].…”