Fundamental Study on Quantitative Evaluation of Acoustic Emisson Signals

为了定量评价声发射信号，我们尝试使用材料中几种声发射产生行为来收集基础数据。第一种行为是Al-Li合金、Ni3Al和TiAl金属间化合物在塑性变形过程中的声发射。确定了移动位错的运动、移动位错与析出相的相互作用、间隙溶质原子和晶界对屈服过程声发射活动的影响。第二种行为是Cu-Al-Ni形状记忆合金单晶马氏体相变过程中的声发射。利用声发射波形分析估计了马氏体的成核和生长速率。第三种行为是Au-Cu合金、PdCu合金和牙科材料在加热/冷却过程中的声发射。在有序/无序转变、有序过程和玻璃化转变点附近检测到声发射，并明确了声发射与这些转变温度的关系。认为利用检测到的声发射信号可以求得扩散控制转化的反应能和扩散的活化能

In order to quantitatively evaluate acoustic emission signals, we tried to collect the fundamental data using several types of acoustic emission generation behaviors in materials. First behavior is the acoustic emission during plastic deformation in Al-Li alloy, Ni3Al and TiAl intermetallic compounds. The effect of movement of mobile dislocations, interaction between mobile dislocations and precipitates, interstitial solute atoms and grain boundaries, respectively, on the acoustic emission activities detected during yielding has been determined. Second behavior is the acoustic emission during martensitic phase transformation in Cu-Al-Ni shape memory alloy single crystals. Nucleation and growth rates of the martensites have been estimated using the acoustic emission waveform analysis. Third behavior is the acoustic emission during heatin/cooling process in Au-Cu alloys, PdCu alloys and dental materials. The acoustic emission was detected in the order/disorder transformation, the ordering process and near the glass transition point, and made clear to relate to these transformation temperatures. It was considered that the reaction energy of diffusion-controlled transformation and the activation energy of diffusion could be evaluated by the detected acoustic emission signals