Al2O3/ZrO2涂层在热等静压致密化TiAl基合金粉末过程中对碳钢包套的影响  

Effects of AlO/ZrO Layers on Carbon Steel Capsule During Consolidation of TiAl Based Alloy Powders by HIP

作　　者：郎泽保[1,2] 张永忠 王亮[1] 张绪虎[1] Lang Zebao;Zhang Yongzhong;Wang Liang;Zhang Xuhu(Division of Special Metals&Processing,Aerospace Research Institute of Materials&Processing Technology,Beijing 100076,China;Composite Center of General Institute of Nonferrous Metals,Beijing 100088,China)

机构地区：[1]航天材料及工艺研究所特种金属及工艺事业部,北京100076 [2]北京有色金属研究总院复合材料中心,北京100088

出　　处：《稀有金属材料与工程》2020年第7期2275-2280,共6页Rare Metal Materials and Engineering

摘　　要：为了确保碳钢包套在热等静压致密化Ti Al基合金粉末过程中的可靠性,本研究利用热喷涂的方法在20#钢包套内壁添加了Al2O3/ZrO2(A-Z)涂层,然后在热等静压试验中,带有A-Z涂层的20#钢包套用于热等静压致密化Ti-46Al-2Cr-2Nb-(W,B)预合金粉末,其工艺为:1523 K/2.5 h,130 MPa+1603 K/0.5 h/130 MPa。为了对比,利用没有A-Z涂层的20#钢包套在1523 K/3 h/130 MPa的工艺参数开展了热等静压致密化试验。利用扫描电镜、电子探针等设施对获得的压坯进行了观测和分析。结果表明:A-Z涂层的加入可以防止脆性金属间化合物的形成。在热等静压过程中,20#钢包套中的Fe原子无法通过扩散的方式与TiAl基合金中的钛原子和铝原子相遇。因此,20#钢包套在热等静压过程中的可靠性得到了保证。此外,通过利用添加A-Z涂层的钢包套获得了完全致密的TiAl基合金压坯,压坯呈现出了近全片层类型的微观组织,其室温下的抗拉强度和延伸率也分别突破了590 MPa和2.0%。In order to ensure reliability of the carbon steel capsule,Al2O3-ZrO2(A-Z)layers were added to the inside wall of the 20#carbon steel capsule via thermal spraying.In the HIP experiment,the capsule with A-Z layers was used to consolidate Ti-46Al-2Cr-2 Nb-(W,B)pre-alloyed powders at 1523 K and 130 MPa for 2.5 h,and then treated via HIP at 1603 K and 130 MPa for 0.5 h.To compare,the 20#carbon steel without A-Z layers was formed via processing of Ti-46Al-2Cr-2 Nb-(W,B)pre-alloyed powders at 1523 K and 130 MPa for 3 h.The as-formed HIPed capsules were observed by SEM and EDS to evaluate the effects of A-Z layers.The test results reveal that the formation of brittle intermetallics is prevented upon addition of A-Z layers.During HIP,iron atoms of 20#carbon steel capsule cannot meet titanium and aluminum atoms in the TiAl based alloy powders by diffusion,hence the reliability of 20#carbon steel capsules is achieved.In addition,the compactly processed capsule of TiAl based alloy with A-Z layers is fully consolidated and it exhibits a fine,nearly full lamellar microstructure.The tensile strength and elongation of the compact at room temperature surpass 590 MPa and 2.0%,respectively.

关 键 词：界面反应 Al2O3/ZrO2(A-Z)涂层 TiAl基合金粉末 热等静压 微观组织 拉伸性能 

分 类 号：TG174.4[金属学及工艺—金属表面处理] TG146.23[金属学及工艺—金属学]