摩擦攪拌加工改善鋁基複合材料機械性質之研究

Enhancing Mechanical Properties of Aluminum Matrix Composites by Friction Stir Processing

莊水旺(S. H. Juang) ； 薛丞碩(C. S. Xue)

《鑄造工程學刊》 40卷4期 (2014/12) Pp. 1-8

摘要

鋁基飛灰複合材料能提升原材料之強度、剛性、耐磨耗性及降低密度等優點；相對地，可能犧牲原材料之延展性及韌性。本研究擬利用摩擦攪拌製程，對ADC6+5wt%飛灰複合材料板狀鑄件施以多路徑（重疊比率22.8%）之摩擦攪拌加工。研究結果顯示，鋁基飛灰複合材料鑄件經摩擦攪拌加工後，鑄件內部飛灰顆粒遭受外力擠壓而產生破碎，原始添加的飛灰顆粒自微米級細化成奈米級，使得鑄件之晶粒組織獲得明顯細化，且奈米級之飛灰顆粒分散於鋁基材中更為均勻，導致有效提升原複合材料鑄件機械性質之機制。經摩擦攪拌加工之鋁基飛灰複合材料較原始鋁基飛灰複合材料之硬度、降伏強度及拉伸強度分別提升約28%、14%及58%；另伸長率亦由1.19%提升至3.12%。

關鍵字

摩擦攪拌製程 ； 鋁基複合材料 ； 機械性質

並列摘要

Aluminum-fly ash (ALFA) composites have benefits to enhance the strength, rigidity, wear resistance and reduce its density. In contrast, ductility and toughness of raw materials may be sacrificed. In this study, friction stir processing (FSP) was applied to further process ADC6 +5 wt% fly ash composite plate castings using a multi-path mode with an overlap ratio of 22.8%. The results showed that fly ash particles inside the ALFA composite castings under external extrusion operation resulted in fragmentation after being subjected by the friction stir processing. The size of added raw fly ash particles were refined from micro- into nano-scale levels, making the grain structure of ALFA castings achieve significant refinement and the nano-scale fly ashes was more uniformly dispersed in the aluminum substrate. This mechanism should lead effectively improve the mechanical properties of the original ALFA castings. As compared to ALFA composites, the hardness, yielding strength and ultimate strength of ALFA+FSP composites were increased about 28%, 14% and 58%, respectively. In addition, the elongation rate was increased from 1.19% to 3.12%.

並列關鍵字

Friction stir processing ； FSP ； aluminum matrix composites ； mechanical properties