(1. 蘭州理工大學(xué)材料科學(xué)與工程學(xué)院，蘭州730050;
2. 蘭州理工大學(xué)省部共建有色金屬先進(jìn)加工與再利用國(guó)家重點(diǎn)實(shí)驗(yàn)室，蘭州730050)
摘 要: 采用真空感應(yīng)熔煉法冶煉出鎳基合金K4169，通過電解萃取結(jié)合原位SEM分析法研究夾雜物的物相組成、尺寸形貌及成分，并分析夾雜物的分布、來源及形成機(jī)理。結(jié)果表明： K4169合金中的單相夾雜物主要為氧化物、碳化物和氮化物(以TiN、Al2O3、SiO2、TiO2、SiC等為主)，復(fù)合夾雜物主要有硅鋁酸鹽(Al2O3-SiO2、Al2O3 -MgO)、鈦的碳、氮、氧化物(TiC-TiN、TiC-TiO2-TiN)及金屬?gòu)?fù)合氧化物夾雜物(Mo-Ni-Fe-O、Ni-Nb-O)。TiN多分布在Laves相周圍；SiC多分布在棒材邊緣；其余各類氧化物多見于棒材心部縮孔內(nèi)部及周圍。硅鋁酸鹽復(fù)合夾雜物由硅鋁氧化物的單相夾雜碰撞形成；金屬?gòu)?fù)合氧化物夾雜于凝固后期的偏析液中氧化析出；碳氮化物復(fù)合夾雜物的形成機(jī)理有兩類：一類為自發(fā)形核(TiC-TiN、TiC-TiO2-TiN)，另一類為以MgO-Al2O3為核心異質(zhì)形核(TiN)。
關(guān)鍵字: 真空感應(yīng)熔煉；鎳基高溫合金；夾雜物；形成機(jī)理
（1. College of Materials Science and Engineering, Lanzhou University of Technology, Lanzhou 730050, China;
2. State Key Laboratory of Advanced Processing and Recycling of Nonferrous Metals,
Lanzhou University of Technology, Lanzhou 730050, China）
Abstract:A method of electrolytic extraction combined with in-situ SEM analysis was utilized to characterize the inclusions in K4169 Ni-based superalloy prepared by vacuum induction melting (VIM). The phases, compositions, morphologies, distribution and formation mechanism of the inclusions were analyzed by SEM in situ analysis. The results indicate that the inclusions of single phase in K4169 include mainly oxide, nitride and carbide(TiN, Al2O3, SiO2, TiO2 and SiC). The inclusions of composite phases include mainly Al2O3-SiO2, Al2O3 -MgO, TiC-TiN, TiC-TiO2-TiN, Mo-Ni-Fe-O and Nb-Ni-O. TiN inclusions mainly distribute near the Laves phase. SiC inclusions distribute in the edge of the cast ingots. Most oxide inclusions distribute in the shrinkage cavities which locate at the center of the cast ingots. The inclusions of Si and Al oxides become a new aluminosilicate complex composition inclusion by chemical reaction or mechanical combination in K4169 by the VIM. The composite metal oxide inclusions are precipitated from liquid segregation oxidized during the solidification process. There are two types of nitride inclusions. The one is the TiC-TiN and TiC-TiO2-TiN inclusion which grow by means of spontaneous nucleation. The other one is MgO-Al2O3 which provide a heterogeneous nucleus for the growth of TiN. The composite metal oxide inclusions precipitated from liquid segregation are oxidized during the solidification process.
Key words: vacuum induction melting; Ni-based superalloy; inclusions; formation mechanism
