Papers by Keyword: Double Composite

Abstract: Nowadays the development of composite materials has increasing importance. In this study Nextel 440 type alumina fibre reinforced aluminium matrix composite wires were investi-gated. Composite wires produced using the continuous process are suitable to simplify the introduc-tion of fibre reinforcements into aluminium castings as well as the production of double composite, sandwich and preferentially reinforced structures. This paper focuses on the porosity of composite wires because minimizing porosity is the primary condition of good mechanical properties. Compo-site wires were produced with different infiltration pressures (0.83 MPa, 1.03 MPa, 1.24 MPa, 1.52 MPa, 1.65 MPa 1.86 MPa and 2.07 MPa) and different diameters (1 mm and 2 mm) to determine the correlation between infiltration pressure and the porosity of wires. 10 grinded cross-sectional samples were made from each type of composite wires. Based on the micrographs of these samples the volume fraction of aluminium was determined by image analysis, which also yielded informa-tion on the porosity of wires. The results show that there is direct linear correlation between the infiltration pressure and the change in porosity. These findings, however, are valid only for the in-vestigated range of pressure.

Abstract: In this study Nextel 440 type alumina fibre reinforced aluminium matrix composite wires were investigated. Composite wires produced using the continuous process are suitable to simplify the introduction of fibre reinforcements into aluminium castings as well as the production of double composite, sandwich and preferentially reinforced structures. This paper focuses on the porosity of composite wires because minimizing porosity is the primary condition of good mechanical properties. Composite wires were produced with different infiltration pressure (0.83 MPa, 1.03 MPa, 1.24 MPa, 1.52 MPa, and 1.65 MPa) to determine the correlation between infiltration pressure and the porosity of wires. 10 grinded cross-sectional samples were made from each type of composite wires. Based on the micrographs of these samples the volume fraction of aluminium was determined by image analysis, which also yielded information on the porosity of wires. The results show that there is direct (linear) correlation between the infiltration pressure and the decrease in porosity. These findings, however, are valid only for the investigated range of pressure. The measured values were in good agreement with the theoretical model used for comparison.

Abstract: Nowadays, metal matrix composites have many new areas of application owing to their excellent properties - for example their great tensile strength and high Young’s modulus with its relatively low weight. The aim of this work is to an examination of ceramic fibre-reinforced aluminium matrix composite wires made via continuous process. Furthermore, the research will outline the double composite products that are composite wire-reinforced metal matrix composites. Double composites are examined by tensile tests, bending tests and pressing tests. A lot of research has been done on the thermal aging of composite wires and on measuring the impact energy of thermal-aged specimens. The mechanical test shows us that structures reinforced with the composite wires have a notably higher load-carrying capacity than does a structure reinforced directly with fibres or a structure without any reinforcement.

Abstract: The fibre reinforced metal matrix composites (FRMMC-s) are one of the main groups of the composite materials. The composite wires are continuous-fibre-reinforced aluminium matrix composites, which are made by a continuous process. Composite wires already have a few experimental applications for the reinforcement of high voltage electric cables. Other experimental application fields of these materials are the preferential reinforcement of the cast parts. In this way significant decrease in the weight could be achieved. The aim of this study is to show the excellent mechanical properties of the composite wires, and the contact relationship between the mechanical and other properties (i.e. thermoelectric power) and the possibility of their standardized production. The continuous production process of the composite wires and their test results were are shown as well. The difference between the composite wire reinforced double composite structures and direct fibre reinforced blocks were delineated as well. In this paper specimens were examined by tensile tests, bending tests, thermal aging tests and thermoelectric power measurement.