Investigating The Effect of ECAP on Fatigue an‎d Corrosion of Magnesium-Based Biocomposite

10/8/2026 12:00:00 AM

Magnesium bio-composites have garnered significant attention in medical applications, particularly in orthopedics an‎d cardiovascular fields, due to their biocompatibility, biodegradability, an‎d the elimination of secondary surgeries for implant removal. However, the high corrosion rate of magnesium, strength degradation due to corrosion over time, an‎d poor mechanical property under fatigue loading present significant challenges to improving the fatigue life an‎d corrosion resistance of these composites. Consequently, modification processes are essential to enhance their performance. In this study, the fabrication of composites using biocompatible Hydroxyapatite (HA) particles an‎d the application of Equal Channel Angular Pressing (ECAP) a Severe Plastic Deformation (SPD) technique known for enhancing fatigue life an‎d corrosion resistance through grain refinement were investigated. To this end, a Magnesium/2.5 wt% Hydroxyapatite bio-composite was initially fabricated via stir casting utilizing mechanical-electromagnetic stirring. Subsequently, supplementary processing involving two-stage hot extrusion followed by four passes of ECAP via route Bc at 325°C was conducted. The results indicated that after two stages of hot extrusion an‎d four ECAP passes, the grain size was reduced to below 5 µm. Additionally, increases of 19.45% in tensile strength an‎d 18% in compressive strength were observed following the four-pass process. Moreover, the four-pass ECAP process resulted in a 33.6% improvement in fatigue life compared to the bio-composite sample. Furthermore, the four-pass process led to a significant reduction in the corrosion rate, evidenced by a 42.4% decrease in the polarization test, a 54% decrease in the weight loss test after 336 hours, an‎d a 14.4% decrease in the pH monitoring test after 336 hours. The rapid formation of a protective layer was identified as a primary factor in reducing the corrosion rate, while grain refinement an‎d the uniform distribution of reinforcement particles contributed to the enhanced fatigue life.

بيوكامپوزيت منيزيم , تغييرشكل پلاستيك شديد , فرايند پرس كاري در كانال همسان زاويه دار , هيدروكسي آپاتايت , خواص مكانيكي , خستگي , خوردگي

Magnesium bio-composite , Severe Plastic Deformation , Equal Channel Angular Pressing , Hydroxyapatite , Mechanical property , Fatigue , Corrosion

Seyed Ashkan Ghoreishizade

Dr. M. Sedighi