本文關鍵詞：環(huán)保型AZ91D鎂合金直接化學鍍鎳工藝研究　出處：《表面技術》2015年02期 　論文類型：期刊論文

  更多相關文章： 鎂合金 化學鍍 前處理 穩(wěn)定性

【摘要】：目的開發(fā)一種無鉻、低氟、穩(wěn)定的鎂合金直接化學鍍鎳工藝。方法通過SEM,EDX及浸泡實驗、動電位極化曲線、劃格試驗等方法 ,以穩(wěn)定系數(shù)和鍍速等參數(shù)為對象,對比新工藝和傳統(tǒng)工藝對鍍層或鍍液性能的影響。結果在以硫酸鎳為主鹽的基礎液中,添加質(zhì)量濃度為0.5 mg/L的硫脲,鍍液的穩(wěn)定性可得到明顯的提高。在使用硝酸+磷酸酸洗后的鎂合金試樣表面,獲得了良好的腐蝕形貌結構,這種結構有利于增強鍍層與基底間的機械咬合作用。新工藝獲得的鍍層屬高P鍍層(P的質(zhì)量分數(shù)約為11%),在Na Cl溶液中的自腐蝕電位由-1.5 V正移至-0.5 V,腐蝕電流密度降低了約3個數(shù)量級。結論以硫酸鎳主鹽鍍液獲得的鍍層耐蝕性優(yōu)于堿式碳酸鎳主鹽鍍液獲得的鍍層,鍍液的最佳p H=5,化學鍍鎳溫度為82℃。
[Abstract]:Objective to develop a direct electroless nickel plating process for magnesium alloys without chromium, low fluorine and stability. Methods SEMX edX, immersion test, potentiodynamic polarization curve and grid test were used. The effects of the new process and the traditional process on the properties of the coating or the plating solution were compared with the parameters of the stability coefficient and the plating speed. The results were found in the base solution with nickel sulfate as the main salt. The stability of the plating solution can be improved obviously by adding thiourea (0.5 mg/L). Good corrosion morphology was obtained on the surface of magnesium alloy after pickling with nitric acid. This kind of structure is helpful to strengthen the mechanical bite between the coating and the substrate. The coating obtained by the new technology belongs to the high P coating, the mass fraction of which is about 11%). The self-corrosion potential in NaCl solution shifted from -1.5 V to -0.5 V. The corrosion current density was reduced by about 3 orders of magnitude. Conclusion the corrosion resistance of the coating obtained from the nickel sulfate main salt plating solution is better than that obtained from the basic nickel carbonate main salt plating solution. The electroless nickel plating temperature is 82 鈩，

本文編號：1433672