(哈爾濱工業(yè)大學金屬精密熱加工國防科技重點實驗室，哈爾濱 150001)
摘 要: 研究了高溫合金噴射成形過噴粉末凝固組織特征。結果表明：粉末呈相當圓整的球形，內部組織隨顆粒粒度的不同呈現(xiàn)多晶核與單晶核生長及發(fā)達與欠發(fā)達枝晶形態(tài)，粉末粒度在10～200μm之間，冷卻速度在103～106 K/s之間。并從熱傳輸和凝固過程上簡要分析了過噴粉末快速凝固組織的形成機制。
關鍵字: 高溫合金 合金粉末 顯微組織
（National Defense S and T Key Lab of Metal Precision Hot Processing,
Harbin Institute of Technology, Harbin 150001, P. R. China）
Abstract:The microstructure characteristics of over-sprayed Nickel-based superalloy powders were investigated. The results showed that the particle of powder exhibits regular spheroid morphology. The microstructures of particles display multi-sites and single-sites nucleation and well-developed, less-developed dendrites, depending on the size of powders. The size of particle is 10～200 μm, and the cooling rate of powders is 103～106K/s. Formation mechanisms of the powders with different size are explained in terms of the corresponding heat transferring and solidifying histories.
Key words: superalloy; alloy powder; microstructure
