Microstructure and mechanical properties of in situ TiB_2/7055 composites synthesized by direct magnetochemistry melt reaction

磁化学熔体反应法合成TiB_2/7055复合材料的组织和性能(英文)

In situ TiB2/7055 composites were successfully synthesized via magnetic chemical direct melt reaction from 7055 （Al-3B）？Ti system. The phase composition and the microstructure of the composites were investigated by XRD, OM and SEM technologies, and the mechanical and wear properties were tested. The results indicate that with the pulsed magnetic field assistance, the morphologies of in situ TiB2 particles are mainly hexagonal-shape or nearly spherical, the sizes are less than 1 μm, and the distribution of the matrix is uniform. Compared the microstructures of the 7055 aluminum matrix composites synthesized without pulsed magnetic field, the average size ofα（Al） phase with pulsed magnetic field assistance is decreased from 20 to 10μm, the array of the second phase is changed from continuous net-shape to discontinuous shape. With the pulsed magnetic field, the tensile strengths of the composites are enhanced from 310 to 330 MPa, and the elongations are increased from 7.5%to 8.0%. In addition, compared with matrix alloy, the wear mass loss of the composites is decreased from 111 to 78 mg under a load of 100 N for 120 min.

通过磁化学熔体反应法在7055(Al 3%B)Ti反应体系中成功制备TiB2/7055复合材料。利用XRD、OM和SEM等分析检测技术研究复合材料的相组成和微观组织。结果表明,脉冲磁场作用下生成的TiB2颗粒呈多边状或近球形,尺寸小于1μm,均匀分布于基体中。与未施加脉冲磁场的复合材料相比,施加磁场后α(Al)晶粒平均尺寸从20μm减小到约10μm,第二相从连续的网格状分布变为非连续性分布。在磁场作用下,复合材料的抗拉强度从310 MPa提高到333 MPa,伸长率从7.5%提高到8.0%。此外,与基体相比,在载荷为100 N,磨损时间为120 min时,复合材料的磨损量从111 mg降低到78 mg。