(哈爾濱工業(yè)大學(xué) 復(fù)合材料研究所， 哈爾濱 150001)
摘 要: 采用一種新型的制備工藝——電子束物理氣相沉積(EB-PVD)， 制備厚度為0.2mm的Ni-Cr-Al-Y高溫合金箔材，并采用掃描電子顯微鏡(SEM)和透射電子顯微鏡(TEM)等測試手段研究了Ni-Cr-Al-Y高溫合金的微觀組織。結(jié)果表明， 制備態(tài)的樣品中存在柱狀晶， 這是由于制備過程中晶粒長大方式所導(dǎo)致的。 經(jīng)過760℃， 16h真空熱處理后， 柱狀晶轉(zhuǎn)變?yōu)榈容S晶， 并析出γ′相。 拉伸斷口的SEM形貌表明，由于柱狀晶之間組織疏松， 結(jié)合較差， 制備態(tài)樣品沿柱狀晶晶界發(fā)生脆性斷裂， 而熱處理態(tài)樣品的斷口為典型的韌性斷口。 力學(xué)性能的測試結(jié)果表明， 經(jīng)過適當(dāng)?shù)臒崽幚砗螅?Ni-Cr-Al-Y高溫合金的室溫和高溫力學(xué)性能同制備態(tài)時相比，有明顯的改善。 在700℃時，熱處理態(tài)樣品抗拉強度為587.6MPa，應(yīng)變?yōu)?1.3%。
關(guān)鍵字: 電子束物理氣相沉積； 高溫合金箔； 柱狀晶；力學(xué)性能； 脆性斷裂
（State Key Laboratory of Advanced Welding Production Technology, Harbin Institute of Technology, Harbin 150001, China）
Abstract:Ni-Cr-Al-Y superalloy foil with 0.2mm thickness was fabricated by EB-PVD process, and its microstructure and mechanical properties were studied by SEM and TEM as well as mechanical analysis. The results show that there are column crystals in the as-deposited samples, which contribute to growing pattern of grains during the process of superalloy, and column crystals transform into equiaxed crystals after vacuum heat treatment at 760℃ for 16h, and γ′ phase is observed. Factograghs of tensile specimens show that brittle rupture occur along the intergranular of column crystals of as-deposited specimens, which attribute to the loose structures with weak cohesion between column crystals, and the fractures of annealed specimens are tough fractures. Test results of mechanical properties show that mechanical properties at round and high temperature are improved sharply, compared with those as-deposited specimens. The tensile strength of annealed specimens is 587.6MPa,and the fracture strain is 11.3%.
Key words: EB-PVD; superalloy foil; column crystals; mechanical properties; brittle rupture
