研究了不同含量Ce/La(x=0,0.1,0.5,1.0)对AZ91D镁合金显微组织及蠕变性能的影响.通过X射线衍射(XRD)、金相显微镜(OM)、扫描电镜(SEM)及能谱分析(EDX)观察与分析表明,压铸AZ91D镁合金中添加Ce/La后,除了α-Mg,β-Mg_(17)Al_(12)相之外,还生成了新的稀土化合物Al_(11)RE_3(RE=Ce/La)化合物,并且细化了合金显微组织、提高了合金室温和高温力学性能.生成的Al_(11)RE_3(RE:Ce/La)高温热稳定相使AZ91D+xCe/La(x=0,0.1,0.5,1.0)合金在150℃,50MPa下的蠕变抗力优于AZ91D镁合金,1%Ce/La的合金与AZ91D相比,蠕变延伸率低了0.2%,最小蠕变速率从2.30×10~(-8)s~(-1)降低到2.02×10~(-8)s~(-1).蠕变试样的微观组织结构分析表明:AZ91D合金的蠕变机制主要以晶界滑移方式为主,Al_(11)RE_3(RE=Ce/La)热稳定相在晶界处延缓和阻碍了晶界断裂的过程.
The effect of Ce/La on the microstructures and creep property of die-cast AZ91D alloys containing varied contents of Ce/ La (0%, 0. 1%, 0.5%, 1.0% ) was studied. X-ray diffraction, optical microscopy, scanning electron microscopy and energy dis-perse spectroscopy were used to analyze microstructures and creep properties of the alloys at room temperature and high temperature. Results showed that the new phase compositions of die-cast AZ91D alloys adding in a small amount of Ce/La mainly consisted of β-Mg_(17)Al_(12) and Al_(11) RE_3 ( RE = Ce/La) phases. It not only refined the microstructure and improved mechanical properties of alloy but al-so improved the creep resistant properties of alloy. Compared 1% Ce/La with AZ91D, the total strain of alloy decreased 0.2% and the minimum creep rate decreased from 2.30 × 10~(-8)s~(-1) to 2.02 × 10~(-8) s~(-1). The creep resistant of the alloy with the heat-resistant phases was superior to that of AZ91D alloy. The results indicated that the creep mechanism of AZ91D alloy was the grain boundary sliding and the heat-resistant phases postponed the process of creep resistant and improved the creep resistant properties of AZ91D alloy.
参考文献
| [1] | 杨明波,潘复生,张静.Mg-Al系耐热镁合金的开发及应用[J].铸造技术,2005(04):331-335. |
| [2] | Srinivasan A;Pillai U T S;Swaminathan J;Pai B C .Enhanced high temperature properties of low pressure cast AZ91 Mg alloy[J].International Journal of Cast Metals Research,2006,19:265. |
| [3] | 黄德明,刘红梅,陈云贵,唐永柏,涂铭旌.耐热铸造镁合金的研究应用进展[J].轻金属,2005(08):49-54. |
| [4] | 刘子利,丁文江,袁广银,朱燕萍.镁铝基耐热铸造镁合金的进展[J].机械工程材料,2001(11):1-4,33. |
| [5] | 孙丰泉,严有为.抗蠕变耐热镁合金的研究进展[J].铸造设备研究,2004(03):17-18,28. |
| [6] | 李冬升,程晓农.抗蠕变镁合金研究进展[J].材料导报,2006(z1):424-427. |
| [7] | 刘海峰,侯骏,刘耀辉,佟国栋,孟嬴,刘文辉.压铸镁合金高温蠕变研究现状及进展[J].铸造,2002(06):330-335. |
| [8] | 樊昱,吴国华,高洪涛,李冠群,翟春泉.La对AZ91D镁合金力学性能和腐蚀性能的影响[J].金属学报,2006(01):35-40. |
| [9] | 王明星,周宏,王林,李伟,赵宇,李文平.钇和铈对AM50镁合金显微组织和力学性能的影响[J].中国稀土学报,2007(01):69-73. |
| [10] | Mihriban O. Pekguleryuz;A. Arslan Kayo .Creep Resistant Magnesium Alloys for Powertrain Applications[J].Advanced Engineering Materials,2003(12):866-878. |
| [11] | 黄晓锋,王渠东,曾小勤,袁广银,朱燕萍,丁文江.稀土对AM50力学性能及高温蠕变的影响[J].中国稀土学报,2004(04):493-496. |
| [12] | Zhang Jinghuai;Zhang Deping;Tian Zheng;Wang Jun Liu Ke Lu Huayi Tang Dingxiang Meng Jian .Microstructures,tensile properties and corrosion behavior of die-cast Mg-4Al-based alloys containing La and/or Ce[J].Materials Science and Engineering A:Structural Materials Properties Microstructure and Processing,2008,489(02):113. |
| [13] | Li Peijie;Tang Bin;Kandalova E G .Microstructure and properties of AZ91D alloy with Ca additions[J].Materials Letters,2005,59:671. |
| [14] | Lü Yizhen;Wang Qudong;Zeng Xiaoqin;Ding Wenjiang Zhai Chunquan Zhu Yanping .Effects of rare earths on the microstructure,properties and fracture behavior of Mg-Al alloys[J].Materials Science and Engineering A,2000,278:66. |
| [15] | 张剑平,艾云龙,陈乐平.AZ91镁合金的抗高温蠕变性能和腐蚀性能的研究近况[J].铸造,2007(08):779-783. |
| [16] | 申泽骥,李玉胜,冯志军,李德成,马志毅.新型铸造镁合金开发现状[J].铸造,2003(03):153-156. |
| [17] | A. A. Luo .Recent magnesium alloy development for elevated temperature applications[J].International Materials Reviews,2004(1):13-30. |
| [18] | Mihriban O. Pekguleryuz;A. Arslan Kayo .Creep Resistant Magnesium Alloys for Powertrain Applications[J].Advanced Engineering Materials,2003(12):866-878. |
| [19] | Bradai D;Kadi H M .The kinetics of the discontinuous precipitation and dissolution in Mg-rich Al alloys[J].Journal of Materials Science,1999,34:5331. |
| [20] | 李继强,樊自田,王元庆.AZ91镁合金增强改性研究进展[J].材料导报,2006(10):80-83. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%