GH5188合金凝固过程动态原位观察研究

Dynamic in-situ observation of solidification process of GH5188 alloy

利用高温共聚焦激光扫描显微镜对GH5188合金在冷速为10~200℃/min条件下的凝固过程进行动态原位观察,并研究了冷速对GH5188合金凝固过程、凝固组织及析出相的影响。结果表明,GH5188合金的凝固过程为缓慢凝固-快速凝固-缓慢凝固过程,冷速越大,峰值凝固速度越大。冷速影响合金凝固温度,随着冷速的增加,凝固温度逐渐降低,冷速的增加使合金凝固后二次枝晶间距减小,析出相尺寸更均匀细小,有利于减少合金凝固过程的裂纹敏感性,获得了不同冷速下合金二次枝晶间距的预测公式。

The solidification process of the GH5188 alloy at cooling rates of 10-200 ℃/min was dynamically in-situ observed by high-temperature confocal laser scanning microscopy(CLSM).The effects of cooling rates on the solidification process,structure and precipitates of the GH5188 alloy were studied.The results show that the solidification process for the GH5188 alloy is slow-rapid-slow solidification.The higher the cooling rate,the greater the peak solidification rate is obtained.The cooling rate affects the solidification temperature of the alloy,and the solidification temperature decreases with the increase in the cooling rate.With the increase in cooling rate,the secondary dendrite arm spacing of the alloy after solidification decreases.The size of precipitates is more uniform and refined,which is conducive to reducing the crack sensitivity of the alloy during solidification.The secondary dendrite arm spacing prediction formula is obtained under different cooling rates.