Microstructure and properties of β-TCP / Zn - 1Mg composites processed by hot extrusion combination of multi-pass ECAP
Publication Name
Journal of Alloys and Compounds
Abstract
To further improve the comprehensive service performance of Zn, hot extrusion combined multi-pass equal channel angular pressing route were applied to process Zn-1(wt%)Mg alloy and 1(vol%)β-TCP/Zn-1Mg composites. As-cast cylinders specimens with a diameter of 60 mm were finally processed to the ECAP-processed specimens with the dimensions of 15 mm × 15 mm × 120 mm. The evolution and corresponding mechanism of the microstructure, mechanical properties, corrosion behavior, and biocompatibility of 1β-TCP/Zn-1Mg composites and Zn-1Mg components were systematically investigated. As a result, compared with Zn-1Mg alloy, the grain refinement effect of ECAP was enhanced in the 1β-TCP/Zn-1Mg composites with exact the same ECAP conditions. Among all the experimental specimens, the minimum average grain size of 3.0 ± 0.3 µm was achieved in 1β-TCP/Zn-1Mg composites processed by 8 ECAP passes. With the increase of ECAP processing times, the texture strength increased, and the texture direction changed to be (0 0 0 1) base plane parallel to TD-axis. Consequently, the 1β-TCP/Zn-1Mg composites after 8 passes of the ECAP process exhibited the highest compressive yield strength (CYS) of 288.05 ± 6.87 MPa and an elongation greater than 50%. Moreover, these composites also showed a moderate degradation rate of 0.04496 mm·y−1 in the simulated body fluid solution. The in vitro cytotoxicity and cytocompatibility evaluation revealed that both ECAP-processed Zn-1Mg alloy and 1β-TCP/Zn-1Mg composites showed non-cytotoxicity to MC3T3-E1 cells, and the addition of β-TCP could improve the biocompatibility of the experimental materials. Above all, the combination of hot extrusion and ECAP should be a useful route to obtain biodegradable Zn-based materials with excellent comprehensive service performance as orthopedic implants. The 1β-TCP/Zn-1Mg composites, which were processed by hot extrusion and subsequent 8 passes ECAP, exhibited the highest CYS, moderate degradation rate, and good biocompatibility, should be a promising candidate for the application of bone repair and bone replacement.
Open Access Status
This publication is not available as open access
Volume
903
Article Number
163988
Funding Number
51871166
Funding Sponsor
National Natural Science Foundation of China