The Energy Efficiency of the Plasma Electrolytic Oxidation (PEO) Coating Process

该项目将包括在几种金属的PEO期间对单个放电进行高速同步的电气和光学监测，并结合气体成分测量。这将使用一系列波形和电源频率来完成。重点将放在能源消耗机制上，等离子体通道顶部水蒸气气泡的增长被认为是能量吸收的主要来源。众所周知，在khz范围内的高频(使得半周期时间开始接近放电之间的周期)，可以在周期的阴极部分促进放电的形成。PEO不是一种传统的电化学过程，火花只是将金属暴露在等离子体中的氧化剂中，因此阴极放电可以提高能量效率。将利用X射线层析成像技术捕捉3-D孔结构，探索PEO条件与涂层微结构之间的相关性。

The project will involve high speed synchronised electrical and optical monitoring of individual discharges, in combination with gas composition measurement, during PEO of several metals. This will be done using a range of waveforms and supply frequencies. The focus will be on mechanisms of energy consumption, with growth of water vapour bubbles at the top of plasma channels known to be a prime source of energy absorption. It's also known that high frequencies, in the kHz range (such that the half-cycle time starts to approach the period between discharges), can promote formation of discharges during the cathodic part of the cycle. PEO is not a conventional electrochemical process, and sparking simply exposes the metal to oxidizing agents in the plasma, so cathodic discharges could improve the energy efficiency. Correlations will be explored between PEO conditions and coating microstructure, using X-ray tomography to capture 3-D pore architectures.