Department of Materials Engineering, Babol Noshirvani University of Technology, Shariati Avenue, Babol, 47148-71167, Iran.
Department of Materials Engineering, Babol Noshirvani University of Technology, Shariati Avenue, Babol, 47148-71167, Iran.
J Mech Behav Biomed Mater. 2023 Aug;144:105977. doi: 10.1016/j.jmbbm.2023.105977. Epub 2023 Jun 12.
This study used friction stir-back extrusion to fabricate the AZ91 + 3 wt% bioactive glass gradient composite wire. The microstructure, mechanical properties, and corrosion resistance of a material in a simulated body fluid were investigated. Three 2-mm diameter holes with varying hole patterns were drilled in the cross-section of the AZ91 rod to apply 3 wt % bioactive glass to the AZ91 matrix. The results demonstrated that the hole pattern strongly influenced the material's flow in the extruded wire's cross-section. By increasing the distance between the center of the initial rod and the center of the holes, a higher temperature and more uniform distribution of plastic strain are formed during friction stir back extrusion, resulting in uniform distribution of bioactive glass particles and α + β eutectic structure near the surface of composite wires. Introducing bioactive glass particles into the zone near the surface of the AZ91 rod results in the formation of a uniform distribution of bioactive glass particles near the surface and their absence in the central zone of the composite wire. A higher amount of discontinuous β-MgAl phase and α + β eutectic formed at the grain boundaries by increasing the temperature and plastic strain during friction stir-back extrusion. The crystallographic texture of the AZ91 rod changed from prismatic to basal and pyramidal due to the friction stir-back extrusion method. A gradient AZ91-bioactive glass composite wire with ultimate tensile strength, yield strength, elongation, and corrosion resistance 58, 64, 62, and 34%, respectively, greater than AZ91 as-cat rod can be produced by inserting bioactive glass powder using a hole drilling method and applying a friction stir back extrusion process.
本研究采用搅拌摩擦背挤工艺制备了 AZ91+3wt%生物活性玻璃梯度复合线材。研究了模拟体液中材料的微观结构、力学性能和耐腐蚀性。在 AZ91 棒的横截面上钻了三个直径为 2mm 的孔，孔的图案不同，以将 3wt%生物活性玻璃施加到 AZ91 基体上。结果表明，孔的图案强烈影响了挤压线材横截面上材料的流动。通过增加初始棒的中心和孔的中心之间的距离，在搅拌摩擦背挤过程中形成更高的温度和更均匀的塑性应变分布，从而使生物活性玻璃颗粒和α+β共晶结构在复合线材表面附近均匀分布。将生物活性玻璃颗粒引入 AZ91 棒表面附近区域，导致生物活性玻璃颗粒在复合线材表面附近均匀分布，而在其中心区域则不存在。通过增加摩擦搅拌背挤过程中的温度和塑性应变，在边界处形成了更多的不连续β-MgAl 相和α+β共晶。由于采用搅拌摩擦背挤方法，AZ91 棒的晶体织构从棱柱体变为基底和金字塔形。通过采用钻孔方法插入生物活性玻璃粉末并施加搅拌摩擦背挤工艺，可以生产出比 AZ91 铸棒具有更高的拉伸强度、屈服强度、伸长率和耐腐蚀性的梯度 AZ91-生物活性玻璃复合线材，其极限拉伸强度、屈服强度、伸长率和耐腐蚀分别为 58%、64%、62%和 34%。
