Investigation On Preparation, Microstructure And Properties Of Basalt Fiber Reinforced Aluminium Matrix Composites

The continuous basalt fiber is a new type of high-performance inorganicfibers. The mechanical, high temperature and acid corrosion performances ofbasalt fibers have all reached a high level among the majority ofhigh-performance fiber, carrying a broad application prospects. Preparingfrom natural basalt ore, low cost and adequate sources of raw materials arethe advantages in development and application of basalt fibers. In the lastdecade, the basalt fiber industry both in application and research has beenprogressively developed in China. However, there is rarely report in metalmatrix composites using the basalt fibers.In this study, we prepared basalt fiber reinforced aluminum alloycomposites via pressure infiltration process. By analyzing the interfacialstructure and mechanical properties, it was identified the interfacial bondingproblems existed in the basalt fiber reinforced aluminum matrix composites.To solve such issues, the surface coating methods were used to improve themechanical properties of the composites.Through thermodynamic calculations, we analyzed the possibleinterfacial reactions in the composite system during the infiltration process.Taking the Basalt fiber-Aluminum matrix composites as the objective system,the detailed process and mass transportation in the main interfacereaction-Al-SiO₂reaction were discussed, referring to the thermodynamic criterion. The structure of the interface reaction layer was characterized byTEM and EDS.The mechanical tests of basalt fiber reinforced aluminum matrixcomposites showed that the composites have the characteristics of fracturebrittleness. The fracture analysis indicated that the interfacial bondingstrength of the fiber and the matrix is over-strong that the load can not bereasonably allocated between the fiber and the matrix. The decisive factoraffecting the mechanical performance of composites is the highly-bondedinterfacial strength.In order to alleviate the interfacial bonding strength, the basalt fibersurface with three coatings （E.g., Al（PO₃）₃, SiO₂and TiO₂layers） were usedto modified the interfacial bonding between basalt fiber and aluminum matrixwith fiber volume fraction of50%in the composites.The mechanical tests showed that the reaction of TiO₂coating has beeneffectively modified the interfacial layer in the composites comparing withthose without the coating treatment by changing the interfacial reactionsystem. This interface layer between the fiber and matrix interface was tunedinto a more reasonable level. To decrease the brittle fracture tendency of thematerial, the TiO₂coating modified composites can enhance the bendingstrength by27%.