采用真空自耗电弧熔炼法制备了Nb-Ti-Si基超高温合金的母合金锭,在2050℃的熔体温度下实现了合金的有坩埚整体定向凝固.测定了电弧熔炼态与定向凝固试样的室温条件断裂韧性,采用SEM,EDS等方法分析了凝固速率V分别为10,20和50 μm/s的整体定向凝固组织、单边切口梁弯曲试样的断口形貌及裂纹扩展路径,并讨论了其断裂机理.结果表明:合金的整体定向凝固组织主要由沿着试棒轴向挺直排列的横截面为多边形的初生(Nb,X)5Si3 (X代表Ti,Hf和Cr元素)棒与耦合生长的层片状Nbss/(Nb,X)5Si3共晶团(Nbss表示铌基固溶体)组成.整体定向凝固显著提高合金的室温条件断裂韧性KQ,且V=50μm/s时的最高,达16.1 MPa·m1/2,较电弧熔炼态试样的KQ提高了50.5％.定向凝固试样中Nbss与(Nb,X)5Si3沿垂直于受力方向的定向排列以及粗糙的Nbss产生的裂纹桥接和偏转,增大了裂纹扩展阻力,从而提高了合金的室温条件断裂韧性.
参考文献
| [1] | B.P. Bewlay;M.R. Jackson;J.-C. Zhao;P. R. Subramanian;M.G. Mendiratta;J.J. Lewandowski .Ultrahigh-Temperature Nb-Silicide-Based Composites[J].MRS bulletin,2003(9):646-653. |
| [2] | Carrillo-Heian E M;Unuvar C;Gibeling J C et al.[J].Scripta Materialia,2001,45(04):405. |
| [3] | Bewlay B P;Jackson M R;Zhao J-C et al.[J].Metallurgical and Materials Transactions A:Physical Metallurgy and Materials Science,2003,34A(10):2043. |
| [4] | Bewlay B P;Jackson M R;Lipsitt H A .[J].Metallurgical and Materials Transactions A:Physical Metallurgy and Materials Science,1996,27A(12):3801. |
| [5] | Geng J;Tsakiropoulos P;Shao G S .[J].Intermetallics,2007,15(01):69. |
| [6] | Li Z;Peng LM .Microstructural and mechanical characterization of Nb-based in situ composites from Nb-Si-Ti ternary system[J].Acta materialia,2007(19):6573-6585. |
| [7] | Bewlay BP.;Jackson MR.;Reeder WJ.;Sutliff JA.;Lipsitt HA. .SOLIDIFICATION PROCESSING OF HIGH TEMPERATURE INTERMETALLIC EUTECTIC-BASED ALLOYS[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,1995(0):534-543. |
| [8] | P. Guan;X.P. Guo;X. Ding .DIRECTIONALLY SOLIDIFIED MICROSTRUCTURE OF AN ULTRA-HIGH TEMPERATURE Nb-Si-Ti-Hf-Cr-Al ALLOY[J].Acta metallurgica Sinica,2004(4):450-454. |
| [9] | Tian Y X;Cheng G M;Guo J T et al.[J].Advances in Engineering Materials,2007,9(11):963. |
| [10] | Sekido N;Kimura Y;Miura S et al.[J].Journal of Alloys and Compounds,2006,425(1-2):223. |
| [11] | 王勇,郭喜平.凝固速率对Nb-Ti-Si基合金整体定向凝固组织及固/液界面形态的影响[J].金属学报,2010(04):506-512. |
| [12] | Cadirh E;Kaya H;Gunduz M .[J].Materials Research Bulletin,2003,38:1457. |
| [13] | Liu Y;Shazly M;Lewandowski J J .[J].Materials Science and Engineering A:Structural Materials Properties Microstructure and Processing,2010,527A(06):1489. |
| [14] | Terlinde G;Rathjen H J;Schwalbe K H .[J].Metallurgical and Materials Transactions A:Physical Metallurgy and Materials Science,1986,19A(04):1037. |
| [15] | Blenkinsop P A;Evans W J;Flowers H M.Titanium'95Science and Technology[M].London:Institute of Materials,1996:933. |
| [16] | 郑瑞廷,张永刚,陈昌麒,程国安.晶界对全片层组织γ-TiAl合金断裂韧性的影响[J].稀有金属材料与工程,2003(12):1003-1006. |
| [17] | Kim W Y;Tanaka H;Kasama A et al.[J].Intermetallics,2001,9(09):827. |
上一张
下一张
上一张
下一张
计量
- 下载量()
- 访问量()
文章评分
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%