(1. 湖南大學(xué) 材料科學(xué)與工程學(xué)院,長沙 410082;
2. 湖南頂立科技有限公司,長沙 410118)
摘 要: 采用冷噴涂工藝在AZ31鎂合金上制備純Al涂層和Al-50%Al2O3復(fù)合涂層。通過掃描電鏡(SEM)、能譜儀(EDS)、材料分析軟件探討Al2O3顆粒的加入對(duì)純Al涂層顯微組織的影響。用電化學(xué)工作站、顯微硬度計(jì)和磨耗試驗(yàn)機(jī)來對(duì)涂層的性能進(jìn)行表征,分析Al2O3顆粒的加入對(duì)純Al涂層耐蝕性、顯微硬度和磨損性能的影響。結(jié)果表明:與純Al涂層相比,復(fù)合涂層組織更致密,孔隙率更低,硬度從51.2HV0.025提高到94.8HV0.025,滑動(dòng)磨損率降低80.5%,磨粒磨損率降低40%。復(fù)合涂層的自腐蝕電流密度(2.36×10-7 A/cm2)和純Al涂層的自腐蝕電流密度(1.19×10-7 A/cm2)相近,相對(duì)于鎂合金的(2.56×10-4 A/cm2)降低3個(gè)數(shù)量級(jí),可以大大提高鎂合金的抗腐蝕性能。
關(guān)鍵字: 冷噴涂;AZ31鎂合金;復(fù)合涂層;耐蝕性;耐磨性
(1. College of Materials Science and Engineering, Hunan University, Changsha 410082, China;
2. Advanced Corporation for Materials & Equipments Co., Ltd., Changsha 410118, China)
Abstract:The pure Al coating and Al-50% Al2O3 composite coating were deposited on AZ31 magnesium alloy by cold spraying. The effect of addition Al2O3 particles on morphology of the pure Al coating was analyzed by scanning electron microscopes(SEM), energy dispersive spectroscopy(EDS) and material analysis software. The effects of Al2O3 particles adding on corrosion resistance, micro-hardness and wear properties of the pure Al coating were studied by using electrochemical workstation, microhardness tester, abrasion tester to evaluate the properties of coatings. The results show that the composite coating possessed higher density, lower porosity, the microhardness increases from 51.2 HV0.025 to 94.8 HV0.025, the sliding wear rate decreases by 80.5% and the abrasive wear rate reduces by 40% in comparison to the pure Al coating. The corrosion current densities of the composite coating (2.36×10-7 A/cm2) and the pure Al coating(1.19×10-7 A/cm2) show the same level, but they are about 3 orders of magnitudes low compared with that of magnesium alloys substrate(2.56×10-4 A/cm2), which can significantly improve the corrosion resistance of magnesium alloys.
Key words: cold spray; AZ31 magnesium alloy; composite coating; corrosion resistance; wear resistance


