鋁合金表面納米化--微弧氧化復合涂層摩擦行為

Tribological behavior of SNC-MAO composite coatings formed on the surface of aluminum alloys

摘要: 通過表面機械研磨處理在LY12CZ鋁合金表面制備表面納米化(SNC)過渡層,再采用微弧氧化(MAO)技術對納米晶過渡層進行微結構重構,設計制備出納米化-微弧氧化(SNC-MAO)復合涂層,并對比研究了鋁合金表面微弧氧化涂層及納米化-微弧氧化復合涂層的摩擦學行為.與微弧氧化涂層相比,納米化-微弧氧化復合涂層因硬度較高而具有較好的耐磨性.微弧氧化涂層及納米化-微弧氧化復合涂層與GCr15鋼球對磨時具有相同的磨損機理,為對磨鋼球向涂層的材料轉移和氧化磨損.

Abstract: A duplex process was designed to modify the surface of LY12 CZ aluminum alloy by using surface mechanical attrition treatment(SMAT) prior to microarc oxidation(MAO). A surface nanocrystalline(SNC) layer was formed on the alloy surface by SMAT,a ceramic outer layer grew on the SNC layer by MAO,and finally an SNC-MAO composite coating was fabricated. The tribological behaviors of the MAO coating and SNC-MAO composite coating were comparatively evaluated. Experimental results showed that the SNC-MAO composite coating had a better wear resistance than the MAO coating in the same test condition due to a higher hardness of the ceramic coating. The wear mechanism of the MAO coating and SNC-MAO composite coating involved materials transfer from the steel ball to the coating and oxidation wear.