采用OM,SEM,XRD研究不同的冷却方式炉冷(Furnace Cooling,FC)、空冷(Air Cooling,AC)和水淬(WaterQuenching,WQ)对半固态Ti14合金微观组织形貌以及相组成的影响.结果表明:3种冷却方式均没有改变合金的相组成,但影响Ti_2Cu相的形态和分布.炉冷后,Ti_2Cu相以颗粒状按一定位向析出,并排列形成条状和树枝状;空冷后,Ti_2Cu相以颗粒状和层片状分布于晶内和晶界;水淬后,晶界液相特征明显,晶内和晶界无明显析出.分析认为:半固态Ti14合金冷却过程中经历了包晶凝固,包晶反应发生在液相/β/Ti_2Cu三线交点处,使得三线交点处的溶质分布很不规则,包晶相的形核和生长形态发生改变,同时,冷却方式不同影响包晶反应程度,从而影响后序的共析组织,使得不同冷却方式冷却后产生了不同的组织形貌.
The microstructure and phase composition of semi-solid Ti14 alloy (α-Ti+Ti_2Cu) with different cooling modes (furnace cooling-FC, air cooling-At and water quenching--WQ) were investigated by OM, SEM and XRD. The results show that the three cooling modes have no effects on the phase composition of Ti14, but influence the morphology and distribution of Ti_2Cu. Tile microstructure of Ti14 after furnace cooling consisted of granular Ti_2Cu precipitates, which distributed in a certain direction presenting strip and dentritic structure. After air cooling, Ti_2Cu precipitates were granular or lamellar in the grains and grain boundaries; while after water quenching, the microstructure was composed of coarse grain boundary, and no evident precipitates were observed. The semi-solid Ti14 alloy undergoes periteetic solidification during cooling process. The peritectic reaction occurs in the liquid/β/Ti_2Cu trijunctions region, which makes the solute distribution there irregular, and the trijunctions dynamics quite complicated. Meanwhile the cooling modes also influence the peritectic reaction extent, and thus affect the following eutectoid, resulting in different microstrncture with different cooling modes.
参考文献
| [1] | Zhao YQ;Wu WL;Chang H .Research on microstructure and mechanical properties of a new alpha+Ti2Cu alloy after semi-solid deformation[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2006(1-2):181-186. |
| [2] | Zhao Y Q;Wu W L;Ma X D et al.[J].Materials Science and Engineering A:Structural Materials Properties Microstructure and Processing,2004,373:315. |
| [3] | 那顺桑.金属热处理300问[M].北京:化学工业出版社,2007:1. |
| [4] | 曾卫东,周义刚.冷速对TC11合金β加工显微组织和力学性能的影响[J].金属学报,2002(12):1273-1276. |
| [5] | 王宥宏,孙占波,周轩,宋晓平.冷却速度对CuCr25合金凝固过程的影响[J].稀有金属材料与工程,2006(08):1289-1293. |
| [6] | 蒋冰轮,李双明,刘林,傅恒志.定向凝固速率对Cu-7.9%Co包晶合金凝固组织的影响[J].稀有金属材料与工程,2006(11):1712-1715. |
| [7] | G. Gonzalez;G.A. Lara-Rodriguez;A. Sandoval-Jimenez .The influence of cooling rate on the microstructure of an Al-Ni hypereutectic alloy[J].Materials Characterization,2008(11):1607-1612. |
| [8] | Tae-Hoon Kim;Jong Hyuk Baek;Jun Hwan Kim;Byoung Kwon Choi;Yong Hwan Jeong;Chang Sun Kang .The effects of heat treatments on the microstructure and mechanical properties of the Ti-2.19Al-2.35Zr alloy[J].Nuclear engineering and design,2008(6):1286-1294. |
| [9] | 张宝昌.有色金属及其热处理[M].西安:西北工业大学,1993:31. |
| [10] | 赵永庆 et al.[P].Chinese Patent,ZL 971123020,1997. |
| [11] | 赵永庆,赵香苗,朱康英.Ti-Cu-Al合金的阻燃特性和微观组织[J].稀有金属材料与工程,1998(06):360-362. |
| [12] | Zhu K Y;Zhao Y Q;Qu H L et al.[J].Journal of Materials Science,2000,35:5609. |
| [13] | Sajjadia S A;Elahifarb H R;Farhangi H .[J].Journal of Alloys and Compounds,2008,455:215. |
| [14] | 李双明,吕海燕,李晓历,刘林,傅恒志.包晶合金的定向凝固与生长[J].稀有金属材料与工程,2005(02):234-239. |
| [15] | Luoa L S;Sua Y Q;Guoa J J.[J].Journal of Alloys and Compounds,2008(461):121. |
| [16] | 张平则,徐重,张高会,贺志勇,李争显.Ti-Cu表面阻燃钛合金研究[J].稀有金属材料与工程,2005(01):162-165. |
| [17] | 赵永庆,刘军林,周廉.典型β型钛合金元素Cu,Fe和Cr的偏析规律[J].稀有金属材料与工程,2005(04):531-538. |
| [18] | 常辉 .[D].西安:西北工业大学,2006. |
| [19] | Herlach D M .[J].Materials Science and Engineering R:Reports,1994,12(4-5):177. |
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