The investigation of acoustic emission (AE) reveals mixing of avalanche processes in porous 316L stainless steel. One avalanche mechanism relates to the movement of dislocations, the other to crack propagation. Both mechanisms occur under different external tensions: small tension dislodges dislocations while crack propagation occurs at much higher tension close to the mechanical failure point. In an intermediate overlap regime, both effects occur simultaneously. The avalanche related power laws show a mixing behavior where the higher avalanche exponents form an upper limit for the mixing curve and the lower exponent is approached asymptotically for strong AE signals. The power law probability distribution functions, show a characteristic upwards bend near the crossover between the two mechanisms. The three regimes, namely, the dislocation movement, mixing, and crack propagation, are confirmed by other avalanche characteristics: the sparseness of the AE spectra, the avalanche exponents of energy, amplitude, and duration. Only the crack propagation follows mean field predictions, while the dislocation movements (in confined spaces) deviates significantly from mean field behavior with much greater exponents than those predicted in this approximation. We demonstrate that apparent deviations from scale invariance are, in reality, the result of two superimposed avalanche processes whereby each of them remains scale invariant. The seeming deviations from scale invariance are actually superposition effects.The investigation of acoustic emission (AE) reveals mixing of avalanche processes in porous 316L stainless steel. One avalanche mechanism relates to the movement of dislocations, the other to crack propagation. Both mechanisms occur under different external tensions: small tension dislodges dislocations while crack propagation occurs at much higher tension close to the mechanical failure point. In an intermediate overlap regime, both effects occur simultaneously. The avalanche related power laws show a mixing behavior where the higher avalanche exponents form an upper limit for the mixing curve and the lower exponent is approached asymptotically for strong AE signals. The power law probability distribution functions, show a characteristic upwards bend near the crossover between the two mechanisms. The three regimes, namely, the dislocation movement, mixing, and crack propagation, are confirmed by other avalanche characteristics: the sparseness of the AE spectra, the avalanche exponents of energy, amplitud...

中文翻译：

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多孔 316L 不锈钢在张力作用下的雪崩和混合行为

声发射 (AE) 研究揭示了多孔 316L 不锈钢中雪崩过程的混合。一种雪崩机制与位错运动有关，另一种与裂纹扩展有关。两种机制都在不同的外部张力下发生：小的张力会移动位错，而裂纹扩展发生在接近机械故障点的高得多的张力下。在中间重叠机制中，两种效应同时发生。雪崩相关的幂律显示了一种混合行为，其中较高的雪崩指数形成了混合曲线的上限，而对于强 AE 信号则渐近地接近较低的指数。幂律概率分布函数在两种机制之间的交叉点附近显示出向上弯曲的特征。这三种制度，即 位错运动、混合和裂纹扩展由其他雪崩特征证实：AE 光谱的稀疏性、能量、振幅和持续时间的雪崩指数。只有裂纹扩展遵循平均场预测，而位错运动（在密闭空间中）显着偏离平均场行为，其指数比该近似中预测的指数大得多。我们证明，与尺度不变性的明显偏差实际上是两个叠加的雪崩过程的结果，其中每个过程都保持尺度不变。与尺度不变性的表面偏差实际上是叠加效应。声发射 (AE) 的研究揭示了多孔 316L 不锈钢中雪崩过程的混合。一种雪崩机制与位错运动有关，另一种与裂纹扩展有关。两种机制都在不同的外部张力下发生：小的张力会移动位错，而裂纹扩展发生在接近机械故障点的高得多的张力下。在中间重叠情况下，两种效应同时发生。雪崩相关的幂律显示了一种混合行为，其中较高的雪崩指数形成了混合曲线的上限，而对于强 AE 信号则渐近地接近较低的指数。幂律概率分布函数在两种机制之间的交叉点附近显示出向上弯曲的特征。这三种状态，即位错运动、混合和裂纹扩展，由其他雪崩特征证实：