Development Of A Thermogravimetric Analyer For Superalloy Materials At 500~1800℃

Superalloy is a metal material which has been in service for a long time at high temperature and under certain stress and pressure.This material has good thermal properties,oxidation resistance and mechanical strength,and is used in high-temperature components of aerospace and aerospace engines,large industries.Gas turbine high-temperature structural parts,chemical industry and other defense industries,at the same time,a large number of superalloys have entered the civil field,such as building materials,metallurgy,automobiles,medical devices and other industries.At present,the research on the thermal properties of superalloys is mainly based on thermogravimetric analysis.So,the development of thermogravimetric analysis equipment based on thermogravimetric analysis is of great significance.This subject is from the basic project of aerospace defense.It is planned to develop high temperature alloy oxidation resistance test equipment to obtain the anti-oxidation performance of the sample in air.Based on the background and research significance of the project,this paper fully studies the research status of thermogravimetric analysis equipment at home and abroad,and finally develops a thermogravimetric analysis device with a temperature range of 500~1800 ℃.The thermogravimetric analysis device is mainly developed according to the technical indicators,and the overall design scheme is formulated.In terms of hardware design,the thermogravimetric analysis equipment adopts the lower dish structure,the heating furnace adopts the graphite electrode radiant heating method,and the furnace adopts the high temperature resistant material heat insulation.The central part forms a constant temperature heating zone,and the upper part of the furnace body is used to facilitate the sample to be placed in the furnace;the weighing adopts a high-precision electronic balance,and the balance is fixed on the stepping motor guide rail for adjusting the position of the sample,and the sample is suspended by the clamping.The system is hung inside the heating furnace for heating,and the weight and temperature data are transmitted to the industrial computer through the serial port.The software is programmed in LABVIEW development environment.A simple and easy-to-operate man-machine interface is developed.The temperature control algorithm is studied.The precise temperature control,sample movement and precise positioning,sample temperature and quality information acquisition and processing are completed.Finally,the performance of the developed thermogravimetric analysis device was tested.The heating rate was 1~50 ℃/min and the linearity was higher than 0.99.The system tests the static response and dynamic response of the system at 500 ℃;700 ℃;900 ℃;1100 ℃;1300 ℃;1500 ℃;1700 ℃.The temperature overshoot is less than 3%,the stabilization time is less than 40 min,and the steady state error is less than ±1 ℃.The overall conforms to the technical specifications of the design.At the same time,the high temperature oxidation characteristics of stainless steel 304,titanium alloy TC4 and nickel alloy were tested.