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用扭摆测量两种跌锰合金(Mn17.5％和12.8％)和一种铜铝合金(Al13％)的内耗,在发生正和反的马氏体相变的温度范围内各出现一个内耗峰。这种内耗峰出现的条件是必须伴随着马氏体式相变过程的进行。 用含Mn17.5％的铁锰合金作了系统实验,观察到内耗峰的高度随升温(或降温)速度和应力的增加而增高,随振动频率和含碳量的增加而减低。可以用振动一周内试样中转变量愈多内耗也愈大的关系得到统一的解释。 讨论了关于产生内耗峰的机构。认为主要由于马氏体相变是突然间完成,此时扭转的外力可视为常数,从应力和不均匀物质交互作用能的计算,可以证明外力所做的功必须损失一半,因而引起内耗。此外应力感生相变也可以引起很小一部分内耗。
The internal friction of the two down-rolled manganese alloys (Mn17.5% and 12.8%) and one of the copper-aluminum alloys (Al13%) was measured with a twist test and a frictional peak was observed within the temperature range at which both positive and negative martensitic transformations occurred. The appearance of such internal friction peak conditions must be accompanied by martensitic transformation process. A systematic experiment was carried out on a Fe-Mn alloy containing 17.5% Mn. It was observed that the height of the internal friction peak increased with increasing temperature (or cooling rate) and stress, and decreased with increasing vibration frequency and carbon content. One can use vibration within a week the more the amount of change in the internal friction is also a greater explanation of the relationship. Discussed the mechanism for generating internal friction peaks. It is considered that the martensitic transformation is completed abruptly mainly because the external force of torsion can be regarded as a constant. The calculation of the interaction energy between the stress and the inhomogeneous material can prove that the work done by the external force must be halved, resulting in internal friction. In addition stress induced phase change can also cause a small part of the internal friction.