固态和液态镁及镁锂合金的密度

摘要

给出关于固体和液态的镁以及含23.03 at.％和30.02 at.％Li的超轻镁锂合金的密度和热膨胀率的新实验数据.采用膨胀计法和伽马射线衰减技术进行测量,测量的温度范围对于镁为145～1244 K,对于镁锂合金为293～1000 K.直接测量Mg和Mg70Li30合金在固?液相变时的密度变化,建立体积性质与温度的关系和参考表.将所得结果与文献数据进行比较,结果表明,镁锂体系中的共晶成分不是23 at.％Li.研究发现,在0～30 at.％Li范围内,液态镁锂体系的摩尔体积与浓度几乎呈线性关系,和理想混合物的明显不同.%New experimental data are presented on the density and thermal expansion of solid and liquid magnesium and ultralight magnesium–lithium alloys containing 23.03 and 30.02 at.％ Li, respectively. The measurements were performed using the dilatometer method and the gamma-ray attenuation technique in the temperature range from 145 to 1244 K for magnesium and from 293 to ～1000 K for the alloys. The density changes during the solid?liquid phase transition were directly measured for Mg and the Mg70Li30 alloy. The temperature dependences and reference tables of the investigated volumetric properties were developed. A comparison of the obtained results with literature data was made. The study showed that the eutectic composition in the magnesium?lithium system differs from 23 at.％ Li. The concentration dependence of molar volume of the magnesium?lithium liquid system was found to be almost linear in the interval of 0?30 at.％ Li and deviated noticeably from the corresponding dependence for an ideal mixture.