發(fā)布時間：2018-12-17 11:36

【摘要】：鎂合金由于其低密度、高比強度和良好的電磁屏蔽效果等優(yōu)點廣泛應用于航空航天、汽車和電子通訊等領域。鎂合金作為植入材料在醫(yī)學應用領域也有著廣闊的發(fā)展與應用前景,受到了人們越來越多的關注。鎂合金的性能對其作為醫(yī)用材料的應用至關重要。本文選用Zn和Mn作為合金化元素,通過正擠壓和等通道轉(zhuǎn)角擠壓(簡稱ECAP)變形制備出不同狀態(tài)的Mg-1Zn-1Mn合金,分析了正擠壓態(tài)和不同道次下ECAP態(tài)合金的微觀組織、力學性能和腐蝕性能的變化。得出以下主要結(jié)論:(1) ECAP可細化合金晶粒,改變第二相的大小和分布。正擠壓態(tài)合金的平均晶粒尺寸為5.08μm,ECAP 1道次、2道次和4道次合金的平均晶粒尺寸分別為4.89、4.12和5.11 μm。ECAP變形后,合金中的第二相顆粒變得更加細小且彌散分布于基體上。(2)與正擠壓態(tài)相比,ECAP變形處理后,合金的硬度值和抗拉強度降低了,但是伸長率得到了提升。合金的抗拉強度隨著ECAP擠壓道次的增加而下降,其中2道次合金的硬度值和伸長率最高。(3) ECAP 1道次合金的容抗弧半徑和電荷轉(zhuǎn)移電阻最大,腐蝕速率最低,具有最好的耐蝕性能。(4) Mg-1Zn-1Mn合金在37 ℃ SBF溶液中浸泡72 h后,腐蝕產(chǎn)物的主要成分是HA(Ca10(OH)2(PO4)6)、CaCO3和Mg(OH)2。在正擠壓態(tài)和ECAP 1道次的合金中,腐蝕產(chǎn)物層比較致密;ECAP 2道次和4道次的合金的腐蝕產(chǎn)物層疏松多孔。
[Abstract]:Magnesium alloys are widely used in aerospace, automobile and electronic communication due to their advantages of low density, high specific strength and good electromagnetic shielding effect. Magnesium alloys as implant materials also have a broad development and application prospects in the field of medical applications, which has attracted more and more attention. The properties of magnesium alloys are very important for their application as medical materials. In this paper, Zn and Mn are selected as alloying elements to prepare Mg-1Zn-1Mn alloy with different states by positive extrusion and equal channel angular extrusion (ECAP). The microstructure of ECAP alloy under positive extrusion and different pass is analyzed. Changes in mechanical properties and corrosion properties. The main conclusions are as follows: (1) ECAP can refine the grain and change the size and distribution of the second phase. The average grain size of the extruded alloy is 5.08 渭 m ECAP 1 pass, and the average grain size of the 2-pass and 4-pass alloy is 4.89 渭 m.ECAP and 5.11 渭 m.ECAP, respectively. The second phase particles in the alloy became smaller and dispersed on the matrix. (2) compared with the positive extrusion, the hardness and tensile strength of the alloy decreased after ECAP treatment, but the elongation was increased. The tensile strength of the alloy decreases with the increase of ECAP extrusion pass, in which the hardness and elongation of the second pass alloy are the highest. (3) the capacitance arc radius and charge transfer resistance of the ECAP 1 pass alloy are the largest, and the corrosion rate is the lowest. (4) after immersion in 37 鈩，

本文編號：2384141