Study on Improvement in the Oxidation Resistance of TiAl at High Temparatarcs low Ion Implantation

用Ar、Al、Si、Cr、Nb、Mo或Zr等离子注入15 × 10 ~（-2）mm的TiAl试样，加速电压主要为50 keV，剂量主要为10 ~（-1）<21>或1.2 × 10 ~（-1）离子m ~（<21>-1 2.通过常压纯氧循环氧化实验，研究了它们的抗氧化性能，并考察了它们在室温至1200 K的循环氧化温度范围内的氧化时间。采用扫描电镜（SEM）、X射线衍射（XRD）、扫描电镜（SEM）和能谱仪（EDS）等对注入样品和氧化样品进行了常规的金相分析，结果表明：在130 ks的第一近抛物线阶段，注入Ar或Cr促进了氧化，而Al或Si则有效地降低了氧化速率，之后Al的注入导致分离氧化，而Si的注入在800 kS内具有较低的氧化速率，Nb或Mo的注入通过实质上形成Al_2O@D23@而导致优异的抗氧化性在氧化初期，E2尺度减小，Nb剂量的降低降低了合金的抗氧化性，Zr离子注入对氧化初期的几个阶段是有效的。自行车.

TiAl specimens measuring 15 x 1O x (1 or 2) in mm were implanted with Ar, Al, Si, Cr, Nb, Mo or Zr ions at acceleration voltage mainly of 50 keV with dose mainly of 10^<21> or 1.2 x 10^<21> ions m-^2.Their oxidation resistance was assessed by cyclic oxidation tests with temperature varying between room temperature and 1200 K in a flow of purified oxygen under atmospheric pressure.The holding time at temperature was 72 ks (20 h) or 3.6 ks (1 h).Isothermal oxidation tests were also performed.Conventional metallographic examinations were performed for implanted specimens and oxidised specimens using glancing angle XRD, AES, XRD, SEM and EDS.The implantation of Ar or Cr enhances the oxidation, while Al or Si is effective to decrease the oxidation rate during the first near parabolic period of 130 ks, after which the implantation of Al results in breakaway oxidation, while the implantation of Si gives low oxidation rate for at least up to 800 ks.The implantation of Nb or Mo results in the excellent oxidation resistance by forming virtually Al_2O@D23@E2 scales during the initial oxidation periods.The decrease in the Nb dose decreases the oxidation resistance.The implantation of Zr is effective for during the initial few cycles.