高熔点单晶生长用铱坩埚制备技术及应用

The Preparation Technology and Application of Iridium Crucible Used in the Growth of High Melting Point Single Crystals

铱坩埚作为高熔点单晶生长容器具备高温性能优异、耐持久性、温度场均匀、抗氧化中毒、良好的抗热震性等性能。采用高频熔炼热浇铸和热加工制备了大直径铱坩埚，具有材料纯度高、晶粒细小、组织均匀、致密度高、加工性能优异等特点，其高温力学性能、热稳定性和服役寿命等均有明显提高。在不同温度进行退火处理，并进行了显微组织分析和显微硬度测试。结果表明，适当的退火温度和加工率可以降低铱板材的硬度，改善材料的塑性变形及加工能力。获得了适合大直径铱坩埚热加工制度为：退火温度在1300～1500℃，道次加工率为10％～15％。

Iridium crucible has excellent properties, such as excellent high temperature mechanical property, durability, temperature field uniformity, as well as oxidation resistance, thermal shock resistance, and so on. The large diameter iridium crucible was successfully fabricated by high frequency smelting, hot casting and hot processing. The iridium prepared crucible has excellent properties, such as fine crystal grain, homogeneity of structure and dense, good processing performance. And it significantly improved high temperature properties, thermal stability and long life times. The microstructure and Vickers hardness of iridium samples treated at different temperature were analyzed. The results show that the appropriate annealing temperature could reduce the hardness and improve plastic deformation and processing performance. The suitable temperature parameter to fabricate the large diameter iridium crucible is 1300-1500℃, and the pass deformation is 10%-15%.