【摘要】：為了優(yōu)化滲鋁鈮合金的微弧氧化工藝和了解復合涂層的抗熱腐蝕性能,利用粉末包埋滲法在鈮合金基體上制備滲鋁層,再通過調整微弧氧化電參數以及添加劑Y(NO_3)_3的含量獲得Al_2O_3陶瓷膜外層,確定最佳工藝參數。以最佳工藝制備復合涂層(MAO-Y/Al/C103),與不含Y(NO_3)_3制備的MAO/Al/C103進行對比,研究其抗熱腐蝕性。結果表明:以微弧氧化膜層的硬度和厚度為主要評價指標,獲得最佳參數為電壓380 V,頻率400 Hz,占空比10%,處理時間30 min。添加Y(NO_3)_3可獲得均勻規(guī)則的多孔形貌;含與不含Y(NO_3)_3制備的試樣相結構一致,都由NbAl_3和γ-Al_2O_3相組成。經900℃混合熔融鹽中熱腐蝕50 h,MAO/Al/C103和MAO-Y/Al/C103試樣都生成Al_2O_3和NaNbO_3相,其熱腐蝕增重量分別為55.71 mg/cm~2和45.59 mg/cm~2。MAO-Y/Al/C103試樣由于在熱腐蝕階段有更多的NaNbO_3生成以及微弧氧化微孔大幅減小,表現出更優(yōu)異的抗熱腐性。
[Abstract]:In order to optimize the micro-arc oxidation process of aluminized niobium alloy and understand the thermal corrosion resistance of the composite coating, the aluminizing layer was prepared on the niobium alloy substrate by powder embedding infiltration method, and then the outer layer of Al_2O_3 ceramic film was obtained by adjusting the electric parameters of micro-arc oxidation and the content of additive Y (NO_3) _ 3, and the optimum technological parameters were determined. The thermal corrosion resistance of composite coating (MAO-Y/Al/C103) prepared by the best process was compared with that of MAO/Al/C103 prepared without Y (NO_3) _ 3. The results show that the hardness and thickness of the micro-arc oxide film are taken as the main evaluation indexes. The optimum parameters are as follows: voltage 380 V, frequency 400 Hz, duty cycle 10%, treatment time 30 min.. Uniform and regular porous morphology can be obtained by adding Y (NO_3) _ 3, and the phase structure of the sample prepared without Y (NO_3) _ 3 is the same as that of the sample prepared without Y (NO_3) _ 3, and all of them are composed of NbAl_3 and 緯-Al_2O_3 phases. After hot corrosion in mixed molten salt at 900 鈩，

本文編號：2528938