(浙江大學(xué) 材料與化學(xué)工程學(xué)院，杭州 310027)
摘 要: 采用酸性AlCl3-EMIC室溫熔鹽對(duì)AZ91D鎂合金表面電沉積制備鋁鍍層，研究不同酸浸蝕處理對(duì)鍍層與基體結(jié)合力的影響。采用刻劃撕扯法對(duì)結(jié)合力進(jìn)行判斷，利用金相顯微鏡(OM)、SEM、EDS、XRD和XPS對(duì)鍍層及酸浸蝕表面形貌、物相組成、元素價(jià)態(tài)進(jìn)行觀察和分析，采用鹽霧實(shí)驗(yàn)法對(duì)鍍層耐蝕性進(jìn)行測(cè)定，并對(duì)鍍層形貌的形成機(jī)理進(jìn)行討論。結(jié)果表明：對(duì)鎂合金表面進(jìn)行機(jī)械預(yù)處理后進(jìn)行電沉積，得到的鍍層不致密，且與基體的結(jié)合較差；對(duì)鎂合金進(jìn)行HF浸蝕后，僅能在鎂合金表面得到致密均勻的鋁鍍層；而以稀磷酸為浸蝕液能同時(shí)改善鍍層的致密性與基體的結(jié)合性能，鍍層經(jīng)兩次撕扯后未脫落，對(duì)基體能起到良好的保護(hù)作用。
關(guān)鍵字: AZ91D鎂合金；室溫熔鹽；鋁；酸浸蝕
（College of Materials Science and Chemical Engineering, Zhejiang University, Hangzhou 310027, China）
Abstract: The effects of different acid pickling processes on the adhesions between the AZ91D magnesium alloy substrate and aluminum coatings electrodeposited from the acid AlCl3-EMIC room temperature molten salts were studied. The adhesions were estimated by score-tearing test. The surface morphology, phase compositions and element valence of coatings/etched substrate were analyzed by OM, SEM, EDS, XRD and XPS. The corrosion resistance was tested by salt-spray. The formation mechanism of coating morphologies was also discussed. The results show that the aluminum coating is not dense and the adhesion between the coatings and substrate is not good after mechanical pretreatment on AZ91D substrate. The dense and uniform coatings can be electrodeposited on the AZ91D substrate after pretreated by hydrofluoric acid pickling. The density of coatings and the adhesion can be improved simultaneously by using diluted phosphoric acid as pickling solution, and thus, the coating provides good protection to the substrate.
Key words: AZ91D magnesium alloy; room temperature molten salts; aluminum; acid pickling
