| ZrO2(Y2O3)含量对双峰晶粒度分布Mo-12Si-8.5B-ZrO2(Y2O3)复合材料力学性能的影响 |
| |
| 引用本文： | 颜建辉,康蓉,唐幸,汪异,邱敬文.ZrO2(Y2O3)含量对双峰晶粒度分布Mo-12Si-8.5B-ZrO2(Y2O3)复合材料力学性能的影响[J].复合材料学报,2021,38(11):3747-3756. |
| |
| 作者姓名： | 颜建辉 康蓉 唐幸 汪异 邱敬文 |
| |
| 作者单位： | 1.湖南科技大学 材料科学与工程学院，湘潭 411201 |
| |
| 基金项目： | 国家自然科学基金 (51475161)；湖南省自然科学基金(2020 JJ4025) |
| |
| 摘 要： | 多相Mo-12Si-8.5B合金是一种很有应用前景的高温结构材料，为了同时提高Mo-12Si-8.5B合金的强度和韧性，提出了采用纳米ZrO2(Y2O3)强韧化具有双峰晶粒度分布Mo-12Si-8.5B复合材料的方法。首先采用溶胶-凝胶和高温氢还原法制备了纳米Mo-ZrO2(Y2O3)复合粉末，然后以纳米Mo-ZrO2(Y2O3)粉末和微米Mo粉末为原材料，采用放电等离子烧结(SPS)技术制备了具有双峰晶粒度分布的Mo-12Si-8.5B-ZrO2(Y2O3)复合材料。结果表明，随着ZrO2(Y2O3)含量的增加，制备的Mo-ZrO2(Y2O3)纳米粉末的粒度和烧结体相对致密度均逐渐减小，ZrO2(Y2O3)含量小于2.5wt%时，烧结体的相对致密度均大于98.1%。当ZrO2(Y2O3)含量为1.5wt%和2.5wt%时，复合材料具有较高的硬度(9.76~9.98 GPa)，抗弯强度(672~678 MPa)和断裂韧性(12.68~12.82 MPa·m1/2)。Mo-12Si-8.5B-ZrO2(Y2O3)复合材料中Mo晶粒细化、粗细Mo晶粒的晶界强化和纳米ZrO2(Y2O3)颗粒第二相强化是提高硬度和抗弯强度主要原因；复合材料中粗晶粒Mo和纳米ZrO2(Y2O3)有助于断裂韧性的提高，材料的增韧机制主要是裂纹偏转和裂纹桥接。
|
| 关 键 词： | Mo-12Si-8.5B ZrO2(Y2O3) 双峰晶粒度 力学性能 复合材料 |
| 收稿时间： | 2020-11-12 |
Effect of ZrO2(Y2O3) content on mechanical properties of Mo-12Si-8.5B-ZrO2(Y2O3) composites with bimodal grain-size distribution |
| |
| Affiliation: | 1.School of Materials Science and Engineering, Hunan University of Science and Technology, Xiangtan 411201, China2.Hunan Provincial Key Defense Laboratory of High Temperature Wear Resisting Materials and Preparation Technology, Hunan University of Science and Technology, Xiangtan 411201, China3.Hunan Provincial Key Laboratory of Advanced Materials for New Energy Storage and Conversion, Hunan University of Science and Technology, Xiangtan 411201, China |
| |
| Abstract: | Multiphase Mo-12Si-8.5B alloy is a promising high-temperature structural material. In order to further simultaneously improve the strength and toughness of the Mo-12Si-8.5B alloy, the method of strengthening and toughening the bimodal grain size Mo-12Si-8.5B alloy with adding nano-ZrO2 (Y2O3) particles was put out. Nanometer Mo-ZrO2 (Y2O3) composite powders were successfully prepared by sol-gel and high-temperature hydrogen reduction method, and a series of Mo-12Si-8.5B-ZrO2 (Y2O3) composites with a bimodal grain size distribution were fabricated via spark plasma sintering (SPS) using nanometer Mo-ZrO2 (Y2O3) and micrometer Mo powders as raw materials. The results show that the particle size of Mo powders and the relative density of the sintered body decrease with the increase of the ZrO2 (Y2O3) content. When the ZrO2 (Y2O3) content is less than 2.5wt%, the relative density is above 98.1%. As the content of ZrO2 (Y2O3) are 1.5wt% and 2.5wt%, the composites exhibit the high hardness (9.76-9.98 GPa), flexural strength (672-678 MPa) and fracture toughness (12.68-12.82 MPa·m1/2). Grain refinement of the Mo, grain boundary strengthening of the nanometer/micrometer Mo grains and the second-phase strengthening of the nano-ZrO2(Y2O3) particles attribute to the increase of the hardness and flexural strength. The coarse grain Mo and nanometer ZrO2 (Y2O3) in the composites contribute to the improvement of the fracture toughness. The toughening mechanisms of the Mo-12Si-8.5B-ZrO2 (Y2O3) composites are crack deflection and crack bridging. |
| |
| Keywords: | |
|
| 点击此处可从《复合材料学报》浏览原始摘要信息 |
|
点击此处可从《复合材料学报》下载全文 |
|
