满足航空发动机铝裙部要求,以Al-Nb-B2O3-CuO为反应体系,6063铝合金熔体为接触反应介质,反应完成后,用近液相线浇铸法制备了含原位颗粒的6063铝基复合材料。探索了反应物摩尔比和预热温度对原位反应过程和产物的影响,以确定原位反应产物特征对复合材料的组织和质量的影响。热力学计算,DSC分析,实验表明,当Al-Nb-B2O3-CuO的反应物摩尔比为6:1:1:1.5时,反应可以继续进行。动力学研究表明,系统中的Al热反应产生了Al2O3和[B],[B]原子与Nb相互作用生成NbB2。随着温度的升高,Nb和AlB2之间的相互作用产生了平均纵向尺寸为1μm的六边形NbB2颗粒和平均纵向尺寸为0.2μm的亚球形Al2O3颗粒。复合材料的微观结构相当精细,估计等轴晶体尺寸约为22μm,170兆帕的抗拉强度,135MPa的屈服强度,伸长率为13.4%,断裂能量为17.05×105KJ/m3,复相颗粒含量为2.3wt%。与未添加的基体合金相比,原位反应产生的NbB2和Al2O3颗粒对合金的显微组织有显著的细化作用,在保持较高的强度和较好的整体力学性能的同时,允许工业大规模生产。
To meet aero-engine aluminum skirt requirements, an experiment was carried out using Al-Nb-B2O3-CuO as the reaction system and a 6063 aluminum alloy melt as the reaction medium for a contact reaction, and 6063 aluminum matrix composites containing in situ particles were prepared with the near-liquid-phase line-casting method after the reaction was completed. The effects of the reactant molar ratio and the preheating temperature on the in situ reaction process and products were explored in order to determine the influence of in situ-reaction-product features on the organization and the qualities of the composites. Thermodynamic calculations, DSC analysis, and experiments revealed that the reaction could continue when the molar ratio of the reactants of Al-Nb-B2O3-CuO was 6:1:1:1.5. A kinetic study revealed that the Al thermal reaction in the system produced Al2O3 and [B], and the [B] atoms interacted with Nb to generate NbB2. With increasing temperature, the interaction between the Nb and the AlB2 produced hexagonal NbB2 particles with an average longitudinal size of 1 μm and subspherical Al2O3 particles with an average longitudinal size of 0.2 μm. The microstructure of the composites was reasonably fine, with an estimated equiaxed crystal size of around 22 μm, a tensile strength of 170 MPa, a yield strength of 135 MPa, an elongation of 13.4%, and a fracture energy of 17.05 × 105 KJ/m3, with a content of 2.3 wt% complex-phase particles. When compared to the matrix alloy without addition, the NbB2 and Al2O3 particles produced by the in situ reaction had a significant refinement effect on the microstructure of the alloy, and the plasticity of the composite in the as-cast state was improved while maintaining higher strength and better overall mechanical properties, allowing for industrial mass production.