论文部分内容阅读
用低频扭摆测量了经过轻度冷加工的Al-0.l％Mg合金在室温时效过程中的内耗变化,观察到表现反常振幅效应的时效内耗峯。用经过充分时效而内耗已达到稳定值的试样进行升温和降温内耗测量,也在30—55℃的温度范围内观察到表现反常振幅效应的温度内耗峯。这些现象在高纯铝试样和经过完全退火的Al-0.l％Mg合金试样中都不出现。 在Al-0.l％Mg合金中也能观察到以前在Al-0.5％Cu合金中所观察到的反常内耗现象,这就排斥了任何用在点阵中所发生的一般脱溶沉淀过程来解释这种反常内耗现象的可能性,困为在含0.1％Mg的铝合金中,在实验测量所涉及的温度范围内,是不能够在点阵中发生一般的脱溶沉淀过程的。 为了解释铝镁合金中所呈现的反常内耗现象的特点,可以假设在铝镁合金中能够形成两种位错气团:一种是“镁原子-空位”对与位错所组成的气团,这种气团能够在应变时效过程中形成;另一种气团是镁原子与位错所组成的气团,当经过范性形变的试样的温度升高到100℃左右时,镁原子与空位脱离,在退火过程中就单独与位错形成气团。前一种气团对于位错的钉札较第二种为强,因而它的振幅内耗峯出现在较高的振幅值。
The internal friction of Al-0.1% Mg alloy after mild cold working at room temperature was measured by low-frequency torsion, and the time-consuming internal friction peak was observed, which showed the abnormal amplitude effect. Internal temperature consumption was measured with a sample that had been sufficiently aged and whose internal friction had reached a steady value, and a temperature internal friction peak exhibiting an anomalous amplitude effect was also observed in the temperature range of 30-55 ° C. These phenomena do not occur in high purity aluminum specimens and in fully annealed Al-0.1% Mg alloy specimens. The same abnormal internal friction observed in Al-0.5% Cu alloys was also observed in Al-0.1% Mg alloys, which excludes any general desolventization process used in the lattice The possibility of explaining this anomalous internal friction problem is that in the aluminum alloy containing 0.1% Mg, a general desolvation precipitation process can not occur in the lattice at the temperature range involved in the experimental measurement. In order to explain the characteristic of abnormal internal friction presented in Al-Mg alloy, it can be assumed that two kinds of dislocation air masses can be formed in Al-Mg alloy: one is the “magnesian-vacancy” pair and dislocation air mass, which The air mass can be formed during strain aging. Another type of air mass is the air mass composed of magnesium atoms and dislocations. When the temperature of the sample after the deformation is increased to about 100 ℃, the magnesium atoms are separated from the vacancies, The process alone and dislocation formation air mass. The former airmail pinch for dislocation than the second is strong, so its amplitude of internal friction peak appears in the higher amplitude value.