为了挖掘亚稳β钛合金Ti-B19的热变形加工潜力,采用热模拟试验机,在温度范围750-1000℃,温度间隔50℃,应变速率为0.001-10s-1的条件下对Ti-B19合金的热压缩行为进行研究.结果表明,一定温度下,Ti-B19合金的流变应力随应变速率的增大而增大;一定应变速率下,合金的流变应力则随温度的升高而降低.当应变ε为0.6时,合金的加工图可分为3个区域.700-800℃,应变速率为0.001-0.1 s-1,合金最大的能量耗散效率值出现在750℃和0.01 s-1处,其数值为42%,出现连续软化之前,此区域的流变曲线中只出现单个峰或振荡峰.第2个区域的温度范围在800-1000℃,应变速率范围为0.001-0.1 s-1,能量耗散效率值在29%～36%之间变化.此区域的流变曲线到达稳态之前只出现单个峰或振荡峰,此时可观察到典犁的再结晶组织.温度低于800℃,应变速率大于0.1 s-1,或者温度高于800 ℃,应变速率大于10 s-1时,合金中会出现典型的流变不稳定的第3区,组织中可观察到绝热剪切带或β相流变不均匀区.
In order to exploit the potential hot deformation ability of metalstable βtitanium alloy Ti-B19 the isothermal compression behavior was investigated by a Gleeble-1500 thermal simulator in the temperature range of 750-1000 ℃ at an interval of 50 ℃ and strain rate from 0.001 to 10 s-1. The results indicate that the flow stress of the alloy increases with increasing of the strain rate at a given temperature, and decreases with the increment of temperature at a given strain rote. The processing map for the alloy obtained at strain of 0.6 can be divided into three domains. The fast is the one in the temperature range of 700-800 ℃ and the strain rate range of 0.001-0.1 s-1, with a peak efficiency of 42% at about 750 ℃ and 0.01 s-1. The flow curves in this domain present a single peak or oscillation in the flow curves before continuous soflening appears. The second is the one in the temperature range of 800-1000 ℃ and the strain rate range of 0.001-0.1 s-1, with efficiency from 29% to 36%. The flow curves in this domain present a single peak or oscillation in the flow curves before reaching steady state. Recrystallized structures can be found, which is a typical dynamic recrystailization zone. The third one is a flow instable domain at the temperature lower than 800 ℃ and the strain rate above 0.1 s-1, or at the temperature higher than 800 ℃ and strain rate above 10 s-1. The adiabatic shear bands (ASBs) and flow inhomogeneous zone of β phases can be observed.
参考文献
| [1] | Eylon D;Shiro Fujishiro;Kishi T.Metallurgy and Technology of Practical Titanium Alloys[M].Warrendale:TMS,1994:29. |
| [2] | 杨冠军,赵永庆,于振涛,周廉.钛合金研究、加工与应用的新进展[J].材料导报,2001(10):19-21. |
| [3] | 陈军,赵永庆,杨海瑛.Ti-B19钛合金绝热剪切带研究[J].热加工工艺,2006(22):17-19. |
| [4] | 常辉,曾卫东,罗媛媛,周义刚,周廉.近β型钛合金Ti-B19时效过程中的相变及显微组织[J].稀有金属材料与工程,2006(10):1589-1592. |
| [5] | Weiss I;Semiatin S L .[J].Materials Science and Engineering,1998,A243:46. |
| [6] | Balasubrahmanyam VV.;Prasad YVRK. .Deformation behaviour of beta titanium alloy Ti-10V-4.5Fe-1.5Al in hot upset forging[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2002(1/2):150-158. |
| [7] | Philippart I;Rack H J .[J].Materials Science and Engineering,1998,A243:196. |
| [8] | Li L X;Lou Y;Yang L B et al.[J].Materials & Design,2002,23(05):451. |
| [9] | Prasad YVRK.;Seshacharyulu T. .Processing maps for hot working of titanium alloys[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,1998(1/2):82-88. |
| [10] | Prasad Y.V.R.K.;Seshachatyulu T. .Effect of Prior #beta#-Grain Size on the Hot Deformation Behavior of Ti-6A1-4V: Coarse vs Coarser[J].Journal of Materials Engineering and Performance,2000(2):153-160. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%