Corrosion Mechanism of Metals and Alloys in CFィイD24ィエD2/OィイD22ィエD2 Plasma Downstream Environments

纯金属（Al、Ti、Cr、Fe、Co、Ni、Cu、Mo、Ta和W）、不锈钢（SUS 304和316）和在CFD 24-O-D22-D2等离子体下游环境中投射铁的相关特性已被研究过。这个研究的主要发现似乎已经概括了，如下面所示。在573 K，纯金属如Ti、Cr、Mo、Ta和W，由腐蚀导致在质量上退化的腐蚀。纯铁、铸铁和不锈钢显示出质量增加，而Al、Co、Ni和Cu在质量中没有变化。Ti、Cr、Mo、Ta和W的腐蚀率在298 - 573 K范围内增加了测试温度。At a given temperature the corrosion rates reached a maximum at O-D22-D2 concentrations of 15 to 20%.2。The emManagement spectrometric analysis of gas phase showed that main gaseous species are F， HF， O， CFイイD23イエD2， COFイD22イD2， and COイD22イD2。The concentration of F and HF reached a maximum when the concentration O-D22 in a feed gas increased to 18%.3。Cr、Mo和Ta的卷曲表面被覆盖在父金属氧化氟的薄薄膜上，而W则被覆盖在金属氟的薄薄膜上的W片上，形成在Co、Ni和Cu上。由存在于Fe和不锈钢中的金属氟和氧氟组成的厚片组成。In the downstream environment of CFイイD24イイD2/OイD22イD2 plasmas， metal fluorides are thermodynamically favored for all the metals examined。MoF型D26型D2、TaF型D25型D2和WF型D26型D2在298至573 K的温度范围内相当高，足以蒸发。因此，在CF D24-D2/O-D22-D2等离子体的下游环境中金属和合金的腐蚀主要是由荧光原子的反应速率控制的，是在等离子体中产生的，以及由反应形成的金属液体压力。

The corrosion characteristics of pure metals (Al, Ti, Cr, Fe, Co, Ni, Cu, Mo, Ta, and W), stainless steels (SUS 304 and 316), and cast iron in downstream environments of CFィイD24ィエD2-OィイD22ィエD2 plasma have been studied. The principal findings of this study are summarized as follows.1. At 573K, pure metals such as Ti, Cr, Mo, Ta, and W suffered from corrosion leading to a decrease in mass. Pure Fe, cast iron and the stainless steels showed an increase in mass, while Al, Co, Ni, and Cu no change in mass. The corrosion rates of Ti, Cr, Mo, Ta, and W increased with rising test temperature in the range of 298 to 573K. At a given temperature the corrosion rates reached a maximum at OィイD22ィエD2 concentrations of 15 to 20%.2. The emission spectroscopic and mass spectrometric analysis of gas phase showed that main gaseous species are F, HF, O, CFィイD23ィエD2, COFィイD22ィエD2, and COィイD22ィエD2. The concentration of F and HF reached a maximum when the concentration OィイD22ィエD2 in a feed gas increased to 18%.3. The corroded surface of Cr, Mo and Ta was covered with a thin film of parent metaloxyfluorides, and that of W with a thin oxide film Thin films of metal fluorides were formed on Co, Ni, and Cu. Thicker films consisting of metal fluorides and oxyfluorides existed on Fe and stainless steels.4. In the downstream environment of CFィイD24ィエD2/OィイD22ィエD2 plasmas, metal fluorides are thermodynamically favored for all the metals examined. The vapor pressures of MoFィイD26ィエD2, TaFィイD25ィエD2 and WFィイD26ィエD2 in the temperature range of 298 to 573K are high enough to evaporate when they are formed. Therefore, the corrosion of metals and alloys in the downstream environment of CFィイD24ィエD2/OィイD22ィエD2 plasmas is primarily controlled by the rates of reactions with fluorine atoms, which are generated in the plasmas, and the vapor pressures of metal fluorides formed by the reactions.