(1. 中國科學(xué)院 力學(xué)研究所，北京 100190；2. 中國科學(xué)院 研究生院，北京 100049)
摘 要: 為描述等離子體電解氧化(PEO)過程中單個(gè)弧光放電通道內(nèi)部及周圍溫度場(chǎng)分布，構(gòu)建圓柱形放電通道模型。采用高速攝像機(jī)和概率統(tǒng)計(jì)方法，測(cè)定鋁合金PEO膜層生長(zhǎng)典型階段弧光放電的弧斑密度及通道尺寸等特征參數(shù)；通過計(jì)算單個(gè)弧光的延遲壽命(140 μs)以及能量，獲得模型參數(shù)。采用Ansys軟件模擬單個(gè)弧光放電通道內(nèi)部及周圍溫度場(chǎng)分布，計(jì)算得出弧光通道中心溫度超過2×104 K，從傳熱學(xué)角度解釋了PEO陶瓷層中γ-Al2O3和α-Al2O3的生成過程以及陶瓷層微結(jié)構(gòu)的形成原因。
關(guān)鍵字: 等離子體電解氧化；單弧光；瞬態(tài)放電；溫度場(chǎng)模擬
arc discharge in plasma electrolytic oxidation process
（1. Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China;
2. Graduate University of Chinese Academy of Sciences, Beijing 100049, China）
Abstract:In order to describe the temperature field distribution around a single discharge channel exactly during plasma electrolytic oxidation (PEO) process, a cylinder-shaped discharge model was designed. In the typical stage of the PEO coating growth on aluminium alloy, by using the high-speed camera and statistical method, the characteristic parameters of discharges, such as the spatial density of arc spot and size of channel, were measured, the lifetime (140 μs) and energy of a single spark were also calculated. The parameters of the model were obtained. The Ansys software was adopted to simulate the temperature field around a single discharge channel. The center temperature of the discharge channel was over 2×104 K. The results can explain the formation of γ-Al2O3 and α-Al2O3 and microstructure in the ceramic coatings from the heat transfer theory.
Key words: plasma electrolytic oxidation; single spark; instantaneous discharge; temperature filed simulation
