Design Of Instrument For Test Of Mechanical Properties Of Ceramics At Extreme-high-temperature

The melting point of Ultra-high Temperature Ceramics is usually higher than3000℃. It is popualar used in the field of Aeronautics and Astronautics for its excellenthigh-temperature strength and oxidation resistance. With the widely application ofUltra-high Temperature Ceramics, the theoretical knowledge and reliability analysis tothe material in ultra high temperature environment have become an increasinglyimportant problem. The traditional method of high temperature furnace is restricted inthe process of testing the properties of the material in high temperature environment forits shortcomings.Design of mechanical performance of Ultra-high Temperature Ceramics testinstrument in extreme temperature is based on the good electrical conductivity itself. Toachieve the target test temperature within a short time,a large current is applied on thetest specimen. The design of instrument is completed in PRO/E,and the component usedin simulation is inputted from PRO/E. As the the target test temperature is higher than2500℃, the measurement of strain and temperature adopted in this design isnon-contact.In addition,the introduction method of current is discussed in this paper,andthis paper also analysises the measurement error in different introduction.This paper takes ZrB2for example. To analysis the temperature distribution on thetest specimen, ANSYS is applied in this paper. In the process of simulation, this paperuses element of SOLID226,SOLID70,FLUID116and SURF152in thermal-electric andthermal-fluid coupling analysis. In the process of simulation, this paper considers thegreat influence of thermal radiation, heat conduction and heat convection to the heatingprocess of test specimen. Meanwhile, this paper descrips each step in the simulationprocess and discusses the setting method of relevant material parameters and elementproperties in detail.The simulation results show that the test specimen can reach2700℃in secondswhile applying a large current on the test specimen based on the electrical conductivityitself. The temperature of test specimen is determined by the value of the current loadedon it. Based on theory of electric heating and theory of thermodynamics, this paperanalysis the results of the simulation. To make sure the force sensor working at propertemperature, this paper improves the shape of fixture.To get a more sensible temperaturedistribution of the test specimen, the shape of specimen is improved. The test system optimized reaches a satisfactory result on both distribution and cooling effect.