CAJ | 학술논문

利用真空热压烧结炉在挤压态AZ61镁合金表面制备了平均粒径为41μm的Mg17Al12-1Er金属涂层。电化学测试结果表明,50μm及以上厚度的涂层耐蚀性基本一致,使镁合金的自腐蚀电位提高500mV以上,自腐蚀电流密度降低2个数量级,极化电阻提高1个数量级,100μm厚的涂层对镁合金基体防护性最佳。在阳极极化的快速析氢条件下,氢气产生时的高压可以将涂层颗粒从涂层中挤出,而在3.5%NaCl溶液中析氢速度较慢,但是在涂层表面会形成氢致裂纹,导致涂层脱落,最终使其失去对基体的保护作用。
이용진공열압소결로재제압태AZ61미합금표면제비료평균립경위41μm적Mg17Al12-1Er금속도층。전화학측시결과표명,50μm급이상후도적도층내식성기본일치,사미합금적자부식전위제고500mV이상,자부식전류밀도강저2개수량급,겁화전조제고1개수량급,100μm후적도층대미합금기체방호성최가。재양겁겁화적쾌속석경조건하,경기산생시적고압가이장도층과립종도층중제출,이재3.5%NaCl용액중석경속도교만,단시재도층표면회형성경치렬문,도치도층탈락,최종사기실거대기체적보호작용。
A vacuum hot-pressing sinter furnace was used to fabricate Mg17Al12-1Er metal coatings whose average particle diameter is 41 μm on the as-extruded AZ61 magnesium alloy surface. Electrochemical measurement results show that the corrosion resistance of the coating is basically identical when the coating thickness is 50 μm or over. The coating makes the corrosion potential of the magnesium alloy increased by 500 mV, the corrosion current density decreased by 2 magnitudes and the polarization resistfince improved by 1 magnitude. The coating of 100 μm in thickness has the best protective performance for the magnesium alloy matrix. Under anodic polarization conditions the hydrogen evolution is very fast. Coating particles can be squeezed out of the coating by high pressure come from the hydrogen formation process. By comparison the hydrogen evolution rate of the coating in the 3.5% NaCl solution is low, but hydrogen-induced cracking can form during the corrosion process, which results in the coating to detach from the magnesium alloy matrix and to lose the protection effect finally.