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采用内氧化法制备ZrO2弥散强化Pt-Ir-Zr高温材料。探讨了内氧化热力学条件,并利用SEM分析内氧化时间对形貌的影响,结合抗拉强度的变化确定最优的内氧化时间。结果表明:在实验条件下会发生Ir、Zr的氧化。Zr比Ir氧化所需的氧分压小。随着内氧化时间的增加,晶粒长大。直到40h后,组织达到稳定。抗拉强度随着内氧化时间的增加呈指数降低。内氧化最优时间为40h。
ZrO2 dispersion strengthened Pt-Ir-Zr high temperature material was prepared by internal oxidation method. The conditions of internal oxidation thermodynamics were discussed. The influence of internal oxidation time on morphology was analyzed by SEM. The optimal internal oxidation time was determined by the change of tensile strength. The results show that under the experimental conditions, oxidation of Ir and Zr occurs. The oxygen partial pressure required for oxidation of Zr is smaller than that of Ir. As the internal oxidation time increases, the grains grow. Until 40h, the tissue reached a stable condition. Tensile strength decreases exponentially with increasing internal oxidation time. The best time for internal oxidation is 40h.