靶基距和锭料蒸发速率对沉积薄板厚度均匀性的影响

Thickness Uniformity Control of Large-Sized Super-Alloy Sheet in Electron Beam Physical Vapor Deposition

电子束物理气相沉积技术被采用制备大尺寸高温合金薄板,靶基距和不同坩埚中锭料蒸发速率对厚度均匀性的影响规律被研究。研究结果表明,靶基距对锭料的有效蒸发效率和厚度均匀性具有重要影响。靶基距低,有效蒸发效率高,反之,靶基距高,有效蒸发效率低。靶基距与锭料的有效蒸发效率成反比关系。调整不同坩埚中锭料蒸发速率,可获得不同的薄板厚度分布。当靶基距为h=50 cm,2号坩埚蒸发量为83%,4号坩埚蒸发量为17%时,沉积薄板厚度分布均匀性最好,在r≤450 mm范围内薄板厚度分布满足国家薄板厚度公差标准。理论计算与实验结果相符合表明模型合理。

The large-sized （ 1.0 m in diameter） super-alloy sheets were synthesized by electron beam physical vapor deposition （EBPVD）. The influence of the growth conditions,including but not limited to the crucible/substrate separa- tions,effective evaporation rates of ingots and pressure,on the thickness uniformity of the super-alloy sheets was theoreti- cally analyzed and experimentally investigated. The results show that the crucible/substrate distances have a major impact on the uniformity of thickness distribution and effective evaporation efficiency. For example,an increasing distance result- ed in a decreased effective evaporation-efficiency and an improved uniformity. Under the compromised conditions： in a dis- tance of 50 cm and the effective evaporation efficiencies of No. 2 and No. 4 crucibles were 83 % and 17 %, respectively, the most uniform super-alloy sheet was deposited with the uniformity of thickness distribution, in a r ≤ 450 rnm area, bet- ter than the national standards for thickness tolerances of sheet. In addition, the calculated and experimental results were found to be in good agreement.