硼粉粒度对Li-B合金结构及热稳定性的影响

分别以3种粒度的硼粉为原料，采用相同的成分配比和工艺参数熔炼制备Li-B合金铸锭。合金铸锭经挤出和轧制获得薄带。随后进行X射线衍射（XRD）测试、扫描电子显微镜（SEM）观察、化学成分分析和热稳定性测试。XRD结果显示，Li-B合金由Li₇B₆相和锂相组成，且Li₇B₆相与锂相的衍射峰强度比随硼粉粒度的增大而减小。SEM观察表明，随原料硼粉粒度的增大，Li-B合金的纤维组织变得粗大且不均匀。化学成分测试显示，Li-B合金中化合态硼含量随硼粉粒度的增大而减小。热稳定性测试表明，原料硼粉的粒度越大，Li-B合金的热稳定性越差。

Effect of Boron Powder Size on Structure and Thermal Stability of Lithium-boron Alloy

The lithium-boron alloy ingots with the same composition were melted under the same process parameters by using three different sized boron powders.The thin-sheets were obtained by extruding and rolling the ingots.Then,they were investigated by XRD,SEM,chemical analysis and thermal stability test.XRD results show that the lithium-boron alloys are composed of Li₇B₆ phase and Li phase.XRD results show that the diffraction intensity ratio of Li₇B₆ phase to Li phase decreases with increase of boron powder size.SEM results show that the fibrous structure in lithium-boron alloy becomes coarse and nonuniform with increased boron powder size.Chemical composition tests show that the fraction of boron in compound is reduced with increase of boron powder size.Thermal stability test shows that the thermal stability of lithium-boron alloy decreases with the increase of boron powder size.