用一步烧结法制备了表面无立方相梯度结构硬质合金,为了解一步烧结梯度结构的形成阶段,探讨冷却速率对梯度结构厚度的影响,实验采用固定时间真空烧结,在1450℃烧结60min后,分别以0.5,1,2,10℃/min的速率冷却.实验结果表明,以上条件均形成了梯度结构组织,梯度结构厚度随着冷却速率的增加而逐渐减小,对应的梯度层厚度分别为58,47.5,31.5,28.7μm.梯度结构厚度与冷却速率(Rc)的指数(eRc)呈线性关系.研究结果揭示了梯度结构在梯度烧结温度和冷却过程两个阶段均能形成.梯度厚度受原子扩散控制.
参考文献
| [1] | W. Lengauer;K. Dreyer .Tailoring hardness and toughness gradients in functional gradient hardmetals (FGHMs)[J].International Journal of Refractory Metals & Hard Materials,2006(1/2):155-161. |
| [2] | Walter Lengauer;Klaus Dreyer .Functionally graded hardmetals[J].Journal of Alloys and Compounds: An Interdisciplinary Journal of Materials Science and Solid-state Chemistry and Physics,2002(1/2):194-212. |
| [3] | SUZUKI H;KOJI H;YASURO T .Beta-free layer formed near the surface of vacuum-sintered WC-beta-Co alloys containing nitrogen[J].Transactions of the Japan Institute of Metals,1981,22(11):758-764. |
| [4] | Li Chen,Enxi Wu,Fei Yin,Jia Li.Effects of gradient structure on the microstructures and properties of coated cemented carbides[J].北京科技大学学报（英文版）,2006(04):363-367. |
| [5] | M.Ekroth;R.Frykholm .Gradient Zones in WC-Ti(C, N)-Co-Based Cemented Carbides: Experimental Study and Computer Simulations[J].Acta materialia,2000(9):2177-2185. |
| [6] | Frykholm R.;Andren HO. .Development of the microstructure during gradient sintering of a cemented carbide[J].Materials Chemistry and Physics,2001(1/3):203-208. |
| [7] | R. Frykholm;M. Ekroth;B. Jansson .Effect of cubic phase composition on gradient zone formation in cemented carbides[J].International Journal of Refractory Metals & Hard Materials,2001(4/6):527-538. |
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%