ABSTRACT

In this investigation, short steel-fibre-reinforced Al, Al-2Mg and Al-4Cu alloy-based composites were prepared by stir casting method. Steel fibres were coated with Cu and Ni by an electroless deposition process for a uniform distribution of fibres in casting. The distribution of steel fibres in an Al matrix was examined using an optical microscope, and elemental distribution across the fibre/metal interface was evaluated by EDX spectroscopy. Electrical resistivity of the as-cast composites was measured as a function of temperature to identify the phase change behaviour of the composites. It revealed a phase change in Al-2Mg-5Fe(Fib)Cu composites in the temperature range between 390 °C and 430 °C due to the dissolution of a copper-enriched phase in the matrix. Samples were solutionised at 450 °C, quenched in water, and aged at 170 °C at various times. Aging temperature was selected based on electrical resistivity data. It is observed that the time to peak hardening of the steel-fibre-reinforced composites is faster than those of base alloys.

摘要

在这项研究中，通过搅拌铸造法制备了短钢纤维增强的Al，Al-2Mg和Al-4Cu合金基复合材料。钢纤维通过化学沉积工艺涂覆有铜和镍，以确保铸件中纤维的均匀分布。使用光学显微镜检查钢纤维在Al基体中的分布，并通过EDX光谱法评估纤维/金属界面上的元素分布。测量铸态复合材料的电阻率随温度的变化，以识别复合材料的相变行为。结果表明，由于富铜相在基体中的溶解，Al-2Mg-5Fe（Fib）Cu复合材料在390°C至430°C的温度范围内发生了相变。将样品在450°C的溶液中溶解，在水中淬灭，并在不同时间在170°C下老化。基于电阻率数据选择老化温度。可以看出，钢纤维增强复合材料的峰值硬化时间比基础合金要快。