为解决Al2O3 短纤维预制体制备周期长、粘结剂偏聚、卸载后易回弹等技术问题, 提出一种真空加压湿法快速成型的新方法. 选择MgCl2·MgF2 作为粘结剂, 成功制备出体积分数分别为10%, 15%, 20%, 25% 的Al2O3 短纤维预制体. 经多次实验确定了预制体制备过程中的工艺参数如下: 45 °C 烘干2 h, 再经梯度加热至1 100 °C 烧结1.5 h. 制得的预制体表观质量良好, 无纤维脱落、分层现象, 纤维及孔隙分布均匀. 压缩实验结果证明, 所制备的预制体可以满足真空压力浸渗的需求.
To solve the problem related with short fiber preform preparation such as long preparing time, binder segregation and dimensional instability when removed from the mold, a new preform preparation technique was proposed. The method was characterized in short preparation time by using vacuum and pressure. MgCl2·MgF2 was selected as an effective binder. A series of alumina preforms with different fiber volume fraction of 10%, 15%, 20% and 25% were successfully fabricated. Processing conditions for the preform preparation were as follows: the preform was dried for 2 hours at 45 °C, and then gradually heated to 1 100 °C within 1.5 hours. The prepared preform had excellent surface quality, good core strength, and uniform pore and fiber distribution without fiber loss. Compression tests showed that the alumina preforms met the requirements of infiltration experiments for fabricating composites.
[1] 卢欣, 杨骁, 宋少沪. 纤维增强聚合物布加固木梁的非线性弯曲分析[J]. 上海大学学报: 自然科学版, 2012, 18(6): 634-639.
[2] Wu S Q, Li J. Application of ceramic short fiber reinforced Al alloy matrix composite on piston for internal combustion engines [J]. China Foundry, 2010, 7(4): 408-411．
[3] Cui J J, Li B C, Zhang G H, et al. Effect of fiber volume fraction on low cycle fatigue behavior of Al2O3sf/Al-Si composites [J]. Applied Mechanics and Materials, 2013, 268: 87-91.
[4] 兖利鹏, 王爱琴, 谢敬佩, 等. 铝基复合材料在汽车领域的应用研究进展[J]. 稀有金属与硬质合金, 2013, 41(2): 44-48.
[5] 凌伟, 张俊乾, 王放. 热/机械载荷作用下金属基复合材料多纤维断裂的应力场[J]. 上海大学学报: 自然科学版, 2006, 12(5): 493-499.
[6] 方峰, 江静华, 谈淑咏, 等. 短纤维预制件强度对铝基复合材料组织的影响[J]. 东南大学学报: 自然科学版, 2002, 32(3): 1-4.
[7] Qi L H, Zhou J M, Su L Z, et al. Fabrication of Cf/Mg composites using extrusion directly following vacuum infiltration-part 2: forming process study [J]. Solid State Phenomena, 2008,
141: 91-96.
[8] 赵文侠, 杨永顺, 郭俊卿. 短纤维增强铝基复合材料预制体制备工艺的研究[J]. 陶瓷学报, 2010, 31(2): 296-302.
[9] 谷雪花. Al2O3sf/AZ91D 复合材料浸渗系统开发及临界浸渗压力研究[D]. 西安: 西北工业大学, 2013.
[10] Lo J S H, Kuriakose A K, Santos R. Preform for magnesium metal matrix composites: US, 6247519B1 [P]. 2001-06-19.
[11] Garoushi S K, Lassila L V, Vallittu P K. Short fiber reinforced composite: the effect of fiber length and volume friction [J]. Journal of Contemporary Dental Practice, 2006, 7(5): 1-9.
[12] Sangani A S, Acrivos A. Slow flow past periodic arrays of cylinders with application to heat transfer [J]. International Journal of Multiphase Flow, 1982, 8(3): 193-206.
[13] 秦振凯. 无压浸渗双尺寸颗粒SiCp/Al 电子封装材料的研究[D]. 西安: 西北工业大学, 2005.
