Quenching and Deformation Dilatometer

淬火和变形膨胀仪可以在不同的工作模式下使用。在淬火模式下，快速感应加热金属样品，加热速度高达几千K/S，温度高达约。通过冷却速度高达1000K/S的气体喷嘴阵列，可以实现1500°C的快速淬火。同时，测量了样品的长度变化。这使金属材料在几乎任何热处理过程中的相变(与足够的体积变化有关)都可以被现场监测。在变形模式(压缩或拉伸)下，这些几乎任意的热处理可以随时停止，以便通过其流动曲线来表征当前温度下的材料状态，即使远离平衡(热机械分析)。以这种方式进行热机械处理的金属样品可以研究其纳米级的材料结构，并作为初始状态，用于通过量热计进行进一步的热分析。一种集成到膨胀学中的原位材料结构分析的新方法是激光超声检测。在这里，样品表面被短激光脉冲轰击，这会在样品内部触发超声波。检测到这种超声波对相反样品表面的影响。超声波的特性，如声速和衰减，可以与材料结构的特性相关联。因此，淬火和变形膨胀仪是罗斯托克大学材料科学教席不可或缺的研究设备，其研究重点是金属材料、热处理工艺/设备、热处理模拟和用于模拟的材料数据/材料模型。热处理工艺还包括本质上与热处理相结合的制造工艺(例如铸造、添加剂制造、热成形、连接)。目前的研究项目包括铝合金的沉淀硬化、铝合金的双辊铸轧、钢的感应淬火、镍钛合金的感应热处理和铜合金的添加剂制造。计划的研究项目包括铝合金的添加制造、添加制造的钢的表面硬化、铝合金的叠加人工时效和蠕变以及高熵合金的烧结。

The quenching and deformation dilatometer can be used in different operating modes. In the quenching mode, rapid inductive heating of metallic samples with heating rates of up to several 1000 K/s to temperatures of up to approx. 1500 °C and subsequent rapid quenching by means of a gas nozzle array with cooling rates of up to several 1000 K/s is possible. In parallel, the length change of the sample is measured. This allows the phase transformations during almost any heat treatment of metallic materials (which are associated with a sufficient volume change) to be monitored in-situ. In the deformation mode (compression or tension), these almost arbitrary heat treatments can be stopped at any time in order to characterise the material state present at the current temperature by its flow curve, even far from equilibrium (thermomechanical analysis). Metallic samples treated thermomechanically in this way can then be investigated with regard to their nanoscale material structure and serve as initial states for further thermal analyses by means of calorimetry.A new method integrated into dilatometry for the in-situ analysis of material structures is laser ultrasonic testing. Here, a sample surface is bombarded with a short laser pulse, which triggers an ultrasound wave inside the sample. The impact of this ultrasonic wave on the opposite sample surface is detected. Characteristics of the ultrasonic wave, such as the speed of sound and the attenuation, can be correlated with characteristics of the material structure. With this equipment, the proposed device has a unique selling point, which opens up completely new possibilities for the applicant to analyse phase transformations in-situ, which are associated with very small volume changes.The quenching and deformation dilatometer is thus an indispensable research device for the Chair of Materials Science at the University of Rostock with its research focus on metallic materials, heat treatment processes/equipment, heat treatment simulations and material data/material models for simulations. Heat treatment processes also include manufacturing processes that are intrinsically combined with heat treatment (e.g. casting, additive manufacturing, hot forming, joining). Current research projects in which the research equipment is to be used include precipitation hardening of Al alloys, twin-roll-casting of Al alloys, induction hardening of steels, inductive heat treatment of Ni-Ti alloys and additive manufacturing of Cu alloys. Planned research projects include additive manufacturing of Al alloys, case hardening of additively manufactured steels, superimposed artificial ageing and creep of Al alloys and sintering of high entropy alloys.