High-Temperature Universal Testing Machine

50 kN高温万能试验机是一种专门设计用于测试、分析和研究纤维增强陶瓷基复合材料热机械性能的独特装置。拉伸、弯曲和压力测试可在室温至1500 °C的空气和冲洗惰性气体中进行。 为了完成这些具有挑战性的任务，该设备配备了两个不同的熔炉。第一个炉由一个长的分裂管式炉（直径100 mm）组成，温度高达1550 °C。第二个是一个短的分体炉（85 mm高），能够测试高达1400 °C的样品。在长管式炉中，拉伸、弯曲和压力测试可在空气和冲洗气体（如氮气或氩气）中进行，温度可高达1500 °C。加载系统的杆系统设计用于脆性陶瓷材料的测试，通过球形轴承，由SiC组成，可以实现这些高测试温度。加载系统、样品夹和样品本身位于长管式炉的热区域，这意味着热环境。因此，最高适用温度在1400 °C时降低至约2 kN。作为替代方法，在短型裂解炉内，拉伸试验可在高达1400 °C时使用50 kN，因为样品夹具和固定装置放置在短型裂解炉外部，温度< 250 °C。这种特殊的设置可以对CMC拉伸样品施加金属载荷和最大力（50 kN），并将其固定在炉外的“冷”环境中。此外，由于炉体积较小，可以节省时间。高温测试的运行速度提高了约三倍，这增加了每天高温测试的数量。短分体炉的另一个优点是使用传统的样品固定装置，可在室温至中等温度下使用。因此，即使是高性能纤维的测试和固定，为了找到从样品夹具朝向陶瓷样品的合适的载荷传递，设计了特定的肩加载夹持装置，其可以由面加载夹具支撑。由于这种设置，在拉伸试验期间可以防止扭矩和弯矩。最后，应该提到应变测量系统，它是独一无二的，就像完整的万能试验机一样。为了防止应变测量仪与样品接触，选择了由激光散斑引伸计组成的非接触式系统。该引伸计可进行应变速度控制测试，无需在样品表面做任何标记。对于弯曲和压力测试，激光引伸计部分适用，并将由线性可变差动Transformer支持。对于室温试验，可使用视频引伸计。

The proposed 50 kN High-Temperature-Universal Testing Machine is a unique device, which is specifically designed, in order to test, analyse and study the thermomechanical properties of fiber reinforced ceramic matrix composites. Tensile-, flexural- and pressure-tests can be conducted from room temperature up to 1500 °C in air and flushing inert gases. In order to fulfil these challenging tasks, the device is equipped with two different furnaces. The first furnace consists of a long, split-tube furnace (diameter 100 mm) with temperatures up to 1550 °C. The second one, a short split furnace (85 mm height), is capable to test samples up to 1400 °C. Within the long, tube furnace tensile-, flexural- and pressure-tests are possible up to 1500 °C in air and in flushing gases, e.g. nitrogen or argon.The rod system of the load train is designed for the testing of brittle ceramic materials, by a spherical bearing and consists of SiC, which enables these high testing temperatures. The load train, the sample clamps and the sample itself is located in the hot region of the long, tube furnaces, which means a hot environment. Therefore, the maximum applicable temperature decreases to about 2 kN at 1400 °C.As an alternative approach, within the short split furnace, tensile tests are possible up to 1400 °C with 50 kN, because the sample clamps and fixtures are placed outside of the short furnace at moderate temperatures < 250 °C. This special setup enables the application of a metallic load train and the maximum force (50 kN) for CMC tensile samples and their fixation outside of the furnace in a "cold" environment.Additionally, due to the lower furnace volume, it is possible to save time. High temperature tests, run about three times faster, which increases the number of high temperatures tests per day. Another advantage of the short split furnace is the use of conventional sample fixtures, which are used at room temperature up to moderate temperatures. Therefore, even for testing and fixation of high performance fibers resp. ceramic fibers the short furnace is suitable up to 1400 °C.In order to find a suitable load transfer from the sample grips towards the ceramic samples, a specific shoulder loaded gripping setup is designed, which can be supported by face loading grips. Due to this setup, torsional- and flexural-moments can be prevented during the tensile tests. Finally, the strain measurement system should be mentioned, which is unique, like the complete universal testing machine. In order to prevent contact of strain measurement gages with the samples a contactless system, which consists of a laser-speckle-extensometer was chosen. This extensometer enable strain-speed controlled tests and do not need any marks on the surface of the samples. For flexural and pressure tests, the laser extensometer is partially suitable and will be supported by a Linear Variable Differential Transformer. For room temperature tests, a video extensometer is applicable.