Mechanical properties modeling of severely plastically deformed biodegradable ZK60 magnesium alloy for bone implants

Abstract

The effectiveness of magnesium (Mg) alloys to improve the capability of bone tissue generation may be severely diminished if the required mechanical properties are not provided. Here, the effort is directed to model the mechanical performance of severely plastically deformed biodegradable ZK60 Mg alloy in bone regeneration protocols. For this purpose, the effects of parallel tubular channel angular pressing (PTCAP) on yield strength (σYS), ultimate tensile strength (σUTS), and elongation to failure (δ) were addressed. Given the multifaceted variables of the PTCAP with nonlinear interactions, a precise determination of the mechanical properties requires a large number of experiments. Therefore, gene expression programming (GEP) and genetic programming (GP) models were proposed to achieve appropriate combinations of mechanical properties for bone implant purposes based on a rational hypothesis that for correlation coefficient (|R|) higher than 0.8, a strong correlation is established between the predicted and measured values. The results verified that the highest mechanical performance was achieved at the second pass of PTCAP, thus has a great potential to be the most promising candidate for biodegradable implant material. Besides, the proposed models were capable of precisely predicting the mechanical performance of the SPD-processed biodegradable ZK60 Mg.

Regulation of corrosion damage of magnesium alloys through the use of vacuum zirconium coatings

“…V W A T D cor 8 76 10 4 . , где W -потеря веса в г, A -площадь поверхности образца в см 2 , Т -время выдержки в коррозионной среде в часах, D -плотность металла в г / см 3 . При этом потеря веса пересчитывалась в количество вещества исходя из того, что 1 моль выделяющегося в процессе реакции (Рис.…”

“…Это связано с их уникальным сочетанием свойств: по плотности и модулю Юнга магниевые сплавы наиболее близки к костной ткани человека и, что наиболее важно, они могут постепенно растворяться в организме, не причиняя ему вреда. В качестве основных перспективных сплавов для применения в медицине рассматриваются как уже известные системы Mg-Zn-Zr [3], так и новые Mg-Zn-Ca и Mg-Y-Zr [4]. Для внедрения и тех и других систем сплавов в медицинскую практику нужно решить две проблемы.…”

Recent Progress on SPD Processes Empowered by Hydrostatic Pressure

“…To resolve the length problem and reduce the processing load, parallel tubular channel angular pressing (PTCAP) was developed based on TCAP, 22) but the sample length problem was not completely solved. PTCAP was successfully accomplished on various types of materials, such as Al-based, 3638) Cubased, 3941) and Mg-based 42) alloys.…”