用真空非自耗电弧熔炼法制备了Nb-16Si-22Ti-2Hf-2Cr-2Al母合金锭,用Y2O3坩埚真空感应熔炼对母合金锭重熔,浇注在温度梯度约为4℃/mm的模壳里,制备出Φ60 mm×170 mm铸锭,研究了1500℃/100 h真空热处理后铸锭的组织特征对室温抗拉强度和高温压缩性能的影响。结果表明,真空感应熔炼Nb-16Si-22Ti-2Hf-2Cr-2Al合金经过1500℃/100 h热处理后,合金锭的组成相为NbSS枝晶,Nb5Si3层片或不规则颗粒和残留Nb3Si块。块状Nb3Si的尺寸越大,发生完全共析转变需要的时间越长、温度越高。热处理合金锭的室温抗拉强度在208~355 MPa之间,室温延伸率变化不大,均小于0.3%。残留的粗大块状Nb3Si和热处理过程中析出的HfO2是导致合金锭拉伸性能较低的重要原因。合金锭的高温压缩强度受到组织中硅化物相含量的影响,压缩强度与硅化物含量成正比。
The master alloy ingot with the nominal composition of Nb-16Si-22Ti-2Hf-2Cr-2Al was prepared by vacuum non-consumable arc-melting and then vacuum induction melting.The melt was poured in a ceramic mould（Y2O3） with the temperature gradient of about 4 ℃/mm.The ingot with the dimension of Φ 60 mm×170 mm was fabricated.Heat treatment was conducted at 1500 ℃ for 100 h.The microstructure,room temperature tensile strength,as well as compression strength at 1250 ℃ of the heat treated ingot were described.Relationship between the microstructure and mechanical properties was also investigated.The results reveal that microstructure of the heat treated ingot is composed of NbSS dendrites,Nb5Si3 particles or lamellae and remaining Nb3Si blocks.Room temperature tensile strength is in the range of 208 to 355 MPa.Both Nb3Si and HfO2 have detrimental effects on the tensile strength.The volume fraction of silicides is in proportion to the high temperature compression strength at 1250 ℃.
参考文献
| [1] | Bewlay B P, Jackson M R, Lipsitt H A. The balance of mechanical and environmental properties of a multi-element niobium-niobium silicide-based in-situ composite [J]. Metallurgical Materials Transactions, 1996, 27(12): 3801-3808. |
| [2] | Guan P, Guo X P, Ding X, et al. Directionally solidified microstructure of an ultra-high temperature Nb-Si-Ti-Hf-Cr-Al alloy [J]. Acta Metallurgica Sinica, 2004(4): 450-454. |
| [3] | Bewlay B P, Jackson M R, Subramanian P R. Processing high-temperature refractory metal silicide in-situ composites [J]. JOM, 1999, 51(4): 32-36. |
| [4] | Ma C L, Li J G, Tan Y, et al. Effect of B addition on the microstructures and mechanical properties of Nb-16Si-10Mo-15W alloy [J]. Materials Science & Engineering A, 2004, 384(1/2): 377-380. |
| [5] | Zelenitsas K, Tsakiropoulos P. Study of the role of Ta and Cr additions in the microstructure of Nb-Ti-Si-Al in situ composites [J]. Intermetallics, 2006, 14(6): 639-659. |
| [6] | Zelenitsas K, Tsakiropoulos P. Study of the role of Al and Cr additions in the microstructure of Nb-Ti-Si in situ composites [J]. Intermetallics, 2005, 13(10): 1079-1095. |
| [7] | Geng Jie, Tsakiropoulos P, Shao Guosheng. A study of the effects of Hf and Sn additions on the microstructure of Nbss/Nb5Si3 based in situ composites [J]. Intermetallics, 2007, 15(1): 69-76. |
| [8] | Kim J H, Tabaru T, Sakamoto M, et al. Mechanical properties and fracture behavior of an NbSS/Nb5Si3 in-situ composite modified by Mo and Hf alloying [J]. Materials Science & Engineering A, 2004, 372(1/2): 137-144. |
| [9] | Geng Jie, Tsakiropoulos P. A study of the microstructures and oxidation of Nb-Si-Cr-Al-Mo in situ composites alloyed with Ti, Hf and Sn [J]. Intermetallics, 2007, 15(3): 382-395. |
| [10] | Kim W Y, Yeo I D, Ra Tae Y, et al. Effect of V addition on microstructure and mechanical property in the Nb-Si alloy system [J]. Journal of Alloys and Compounds, 2004, 364(1/2): 186-192. |
| [11] | 田玉新, 郭建亭, 周兰章, 等. Dy对Nb-Nb5Si3共晶合金显微组织和力学性能的影响[J].金属学报, 2008, 44(5): 589-592. |
| [12] | Tian Y X, Guo J T, Liang Y C, et al. Effect of Ho additions on the microstructure and mechanical properties of Nb-22Ti-16Si-7Cr-3Al-3Ta-2Hf alloys [J]. International Journal Materials Research, 2007, 98: 6-11. |
| [13] | Bewlay B P, Lewandowksi J J, Jackson M R. Refractory metal-intermetallic in-situ composites for aircraft engines [J]. JOM, 1997, 49(8): 44-45. |
| [14] | Sha J B, Hirai Hisatoshi, Tabaru Tatsuo, et al. High-temperature strength and room-temperature toughness of Nb-W-Si-B alloys prepared by arc-melting [J]. Materials Science & Engineering A, 2004, 364(1/2): 151-158. |
| [15] | 姚成方, 郭喜平, 郭海生, 等. 电弧熔炼 Nb-Ti-Si-Cr-Hf-Al-B-Y超高温合金母合金锭的组织形成和成分分布特点[J] . 材料工程, 2007, 增刊: 164-168. |
| [16] | Loria E A. Niobium-base superalloys via powder metallurgy technology [J]. JOM, 1987, 39(7): 22-26. |
| [17] | Gevens A J, Heerden D Van, Foecke T. Fabrication and evaluation of Nb/Nb5Si3 microlaminate foils [J]. Metallurgical and Materials Transactions A, 1999, 30(11): 2959-2965. |
| [18] | Bewlay B P, Lipsitt H A, Jackson M R. Solidification processing of high temperature intermetallic eutectic-based alloys [J]. Materials Science & Engineering A, 1995, 192/193: 534-543. |
| [19] | Yu J L, Zhang K F, Wang G F. Superplasticity of multiphase fine-grained Nb-16Si-2Fe refractory alloy [J]. Intermetallics, 2008, 16(10): 1167-1170. |
| [20] | 贾丽娜, 李小溅, 沙江波, 张虎. 定向凝固对Nb-14Si-22Ti-2Hf-2Al-4Cr合金组织和高低温力学性能的影响[J]. 稀有金属材料与工程, 2010, 39(8): 1475-1479. |
| [21] | 徐惠彬, 高明, 张虎, 等. 氧化钇掺杂氟化锂坩埚及其采用热压烧结制坩埚的方法:中国, 200810101791.1[P]. |
| [22] | Qu S Y, Han Y F, Kang Y W. Effects of Ti, Al and Hf on niobium silicides formation in the Nb-Si in situ composites [J]. Science China Ser E: Tech Sci, 2009, 52(1): 37-40. |
| [23] | Subramanian P R, Mendiratta M G, Dimiduk D M, et al. Advanced intermetallic alloys-beyond gamma titanium aluminides [J]. Materials Science & Engineering A, 1997,239/240: 1-13. |
| [24] | Jia L N, Gao M, Ge J R, et al. Effects of cooling rate and pouring temperature on microstructure and fracture toughness of the induction melted Nb-16Si-22Ti-2Hf-2Cr-2Al alloy [J]. International Journal of Modern Physics B, 2010, 24(15/16): 2149-2153. |
| [25] | Sekido N, Kimura Y, Wei Fugao, et al. Effect of lamellar space on the mechanical properties of (Nb)/(Nb,Ti)5Si3 two-phase alloys [J]. J Japan Inst Metals, 2000, 64(11): 1056-1061. |
| [26] | 聂文金, 王学敏. 铌的熔化与提纯, 铌·科学与技术[M]. 北京: 冶金工业出版社, 2003: 95-96. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%