研究近α型TG6钛合金盘锻件双态组织在600 ℃不同应变幅条件下的低循环疲劳行为,总应变幅△εt/2控制在±0.6%～±1.5%,应变比R＝-1,采用三角波方式加载.结果表明:600 ℃低循环疲劳条件下,随着总应变幅的增加,循环峰值应力smax提高,而疲劳寿命Nf下降;对于TG6钛合金盘锻件双态组织,存在一个循环软化/硬化的总应变幅临界值(△εt/2)c,约为±1.0%,当总应变幅高于此值,表现为循环硬化行为,而低于此值时,则表现为循环软化行为;在所有应变幅条件下,疲劳裂纹均为多源萌生模式,600 ℃低循环疲劳变形行为主要受α晶粒内位错的平面滑移所控制,位错平面滑移集中的结果是最早在α晶粒内萌生疲劳裂纹;随着疲劳测试温度的提高,不同滑移系上位错滑移的临界分切应力的差别缩小,促进位错交滑移的进行.
参考文献
| [1] | HICKS M A;THOMAS M C.Advances in aeroengine materials[A].Ireland:Trinity College Dublin,2003:43-56. |
| [2] | Christoph Leyens;Frank Kocian;Joachim Hausmann;Wolfgang A. Kaysser .Materials and design concepts for high performance compressor components[J].Aerospace science and technology,2003(3):201-210. |
| [3] | LüTJERING G;GYSLER A;ALBRECHT J.Influence of microstructure on fatigue resistance[A].Pergamon:Pergamon Press,1996:893-904. |
| [4] | SATYANARAYANA D V V;VARMA V K;NAGALAKSHMI G;RAO M K S .Creep and fatigue behaviour of a near a IMI 834 titanium alloy[J].Metals Materials and Processes,2007,19:101-110. |
| [5] | GOUTHAMA N S;SINGH V .Low cycle fatigue behavior of Ti alloy Ti metal 834 at 873 K[J].International Journal of Fatigue,2007,29:843-851. |
| [6] | WANG X;VO P;JAHAZI M;YUE S .Dwell fatigue microstructure in a near-a titanium alloy[J].Metallurgical and Materials Transactions,2007,38A:831-839. |
| [7] | Bache MR.;Davies HM.;Evans WJ. .ELECTRON BACK SCATTERED DIFFRACTION (EBSD) ANALYSIS OF QUASI-CLEAVAGE AND HYDROGEN INDUCED FRACTURES UNDER CYCLIC AND DWELL LOADING IN TITANIUM ALLOYS[J].Journal of Materials Science,1997(13):3435-3442. |
| [8] | Evans WJ. .Optimising mechanical properties in alpha+beta titanium alloys[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,1998(1/2):89-96. |
| [9] | WOODFIELD A P;POSTANS P J;LORETTO M H;SMALLMAN R E .The effect of long-term high temperature exposure on the structure and properties of the titanium alloy Ti 5331S[J].Acta Metallurgica,1988,36:507-515. |
| [10] | WANG X;JAHAZI M;YUE S .Substructure of high temperature compressed titanium alloy IMI 834[J].Materials Science and Engineering A,2006,434:188-193. |
| [11] | H.J.Maier;H.J.Christ .Modeling thermomechanical fatigue life of high- temperature titanium alloy IMI 834[J].Metallurgical and Materials Transactions, A. Physical Metallurgy and Materials Science,2000(2):431-444. |
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