My activities in June:

During this month I have prepared publication entitled: Structural investigation of Mg-3Ca, Mg-3Zn-1Ca and Mg-3Zn-3Ca wt.% as cast alloys.

Here you have an abstract:

Magnesium alloys from Mg-Zn-Ca system are interesting, because of possible application as bioresorbable cardiovascular stents or temporary orthopaedic implants. Avoidance of removal surgery is an undeniable advantage of using biodegradable materials.
Alloys of nominal composition Mg-3Ca, Mg-3Zn-1Ca and Mg-3Zn-3Ca (in wt.%) have been prepared by resistance melting and casting into graphite mould under protective argon atmosphere. All investigated alloys have revealed (Mg) dendritic microstructures with intermetallic phases distributed in interdendritic spacing. Except a(Mg), hexagonal ternary phase Ca2Mg6Zn3 has been detected for the Mg-3Zn-1Ca alloy and Mg-3Zn-3Ca (Ca2Mg6Zn3 phase belongs to the space group P63/mmc, with lattice parameters depending on the chemical composition). It was calculated that the unit cell parameters for the ternary phase change - a: from 9.912 to 9.945 Å, c: from 10.351 to 10.378 Å, if compare Mg-3Zn-1Ca to Mg-3Zn-3Ca. The Mg-3Ca alloy contain only Mg2Ca (hexagonal crystal structure; space group P63/mmc, with lattice parameters a = 6.239 Å and c =10.146 Å). The same binary phase has been identified in Mg-3Zn-3Ca alloy, but with slightly changed parameters:
a = 6.2152 Å and c = 10.0699 Å. The hardness of all alloys have been measured. The highest value: 68 HV has been observed for Mg-3Zn-3Ca alloy whereas hardness of alloy containing only calcium was significantly lower: 49 HV. Both existing in materials intermetallic phases segregate on the grain boundaries and harden alloys.