摘要： 對原位反應制備的鋁基復合材料進行了研究。以A356-Na2B4O7-K2TiF6-KBF4為反應體系通過熔體反應法成功制備了TiB2/A356顆粒增強復合材料。研究了TiB2/A356顆粒增強復合材料的微觀組織、相組成以及內生顆粒的形貌、大小及分布特征等，測試了復合材料的力學性能；研究了凝固速度對復合材料組織拉伸性能和沖擊性能的影響，并初步探討了復合材料的強化機制。實驗結果表明按適當實驗方案制備出的復合材料只含兩種顆粒增強相。研究了冷卻速度對TiB2/A356復合材料凝固行為的影響。對TiB2/A356復合材料進行了室溫拉伸性能測試，研究表明：顆粒體積分數(shù)升高，抗拉強度 增大，而延伸率 有降低趨勢；冷卻速度的加快復合材料的拉伸性能顯著提高，抗拉強度 提高，延伸率 提高59%。不同冷卻速度時TiB2/A356顆粒增強復合材料的室溫沖擊韌性研究結果表明：隨著冷卻速度的增大復合材料的沖擊韌性得到提高。

關鍵詞：  TiB2/A356復合材料 原位反應 力學性能 冷卻速度

 

The optimized design of microstructure and properties of TiB2 particulate reinforced A356 Al Based In-situ Composites

Abstract: We had studied about particle-reinforced Al-matrix composites prepared by in-situ reaction. In this study, A356-Na2B4O7-K2TiF6-KBF4 was chosen as reaction system. TiB2/A356 particle-reinforced composites were prepared using melt reaction. Characterization tests have been performed to discuss the microstructures and phases constitution of the composite materials as well as size, appearance and distribution characteristics of the reinforced particles in order to test the mechanical properties; Experiments were carried out to examine the effects of solidification rate on tensile and impact properties of the composite material as well as the strengthening mechanism of the material.It has been observed that the composite materials prepared by the appropriate experimental scheme are only two kinds of particle reinforced phase. The Solidification Behavior of TiB2/A356 composite with different cooling rate were showed. The tensile properties of TiB2/A356 composite materials in room temperature show that as the reinforced particles increases, tensile strength   increases and elongation rate   decreases. The tensile properties of the composite were significantly improved, the tensile strength was improved, and the elongation was increased by 59%.The impact ductility of TiB2/A356 composite materials with different solidification rate in room temperature show that the impact ductility of the composite materials improves as the solidification rate increases. 

Key words: TiB2/A356 composite materials  melt in-situ reaction  mechanical properties  

             cooling velocity