W-Mo系复合材料的制备及其特性波阻抗

 采用放电等离子烧结技术，在相同的温度（1 473 K）及压力（30 MPa）下，制备出不同配比的致密的W-Mo系复合材料样品。采用高精度超声波脉冲回波重合方法，精确测量了超声波在样品中传播的横、纵波声速，并由此得到样品的特性波阻抗值。对样品的相组成分析及电子探针分析的结果表明，W-Mo系复合材料主要是以W、Mo机械混合的形式通过粘结相获得致密化的。因此，选用混合物模型对其特性波阻抗值进行了理论预测，与实测值的比较表明该模型能对W-Mo系复合材料的特性波阻抗作出比较准确的预测。

PREPARATION OF W-Mo COMPOSITES AND THEIR CHARACTERISTIC WAVE IMPEDANCE

Dense W-Mo composites with different mass fractions of W and Mo were prepared at same temperature (1 473 K) and pressure (30 MPa) by using spark plasma sintering technique. The transverse and longitudinal wave velocities of the samples were accurately measured using ultrasonic pulse echo overlap method, so the characteristic wave impedance values of the samples were then obtained. The results of phase composition and electron probe microscope analysis show that the W-Mo composite can be treated as a mechanical mixture system and high coherence between W and Mo grains is achieved due to sintering additives. Therefore, ideal mixture model was adopted to estimate the characteristic wave impedance of W-Mo composites. Comparisons with the experimental results demonstrate that the suggested model is sufficiently accurate to predict the wave impedance value of W-Mo composites.