Development of Measurement Device of Thermal Expansion of Artificial Graphite Materials at High Temperature Background Norio Iwashita AIST (産総研) Japan Artificial graphite materials are used for manufacturing industries, electric furnace steel manufacturing, silicon and SiC semiconductor manufacturing, and aluminum refining. 【熱ストレス抵抗(TSR)】 計測フロンティア研究部門 Application temperature TC ⋅ FS TSR = CTE ⋅ YM ⋅ ER TC: Thermal Conductivity FS: Flexural strength CTE: Coefficient of thermal expansion YM: Young’s Modulus ER: Electrical Resistivity SGL-carbon presented in Carbon2007 TRS : one of the measure for graphite materials applied at high temperate. High temperature CTE could not be measured in my Lab. 2 【熱ストレス抵抗(TSR)】 計測フロンティア研究部門 Application temperature TC ⋅ FS TSR = CTE ⋅ YM ⋅ ER TC: Thermal Conductivity FS: Flexural strength CTE: Coefficient of thermal expansion YM: Young’s Modulus ER: Electrical Resistivity SGL-carbon presented in Carbon2007 TRS : one of the measure for graphite materials applied at high temperate. High temperature CTE could not be measured in my Lab. 3 【Coefficient of thermal expansion】 Aim of this work For measurement of thermal expansion of artificial graphite materials above 2000oC, special electric furnace with the device measuring specimen dimension has been developed on the basis on JIS R2207. “Idea of development” of thermal expansion measurement device of graphite materials at high temperature Material For the measurement at the temperature above 2000 degree-C, we used “isotropic graphite” as furnace heater and measurement jigs. And also as the reference materials for thermal expansion measurement with contact method, isotropic graphite was used. 6 Idea 1 Measurement System 計測フロンティア研究部門 extensometer Differential transformer (spring gage) Detector rod thermocouple Laser microgage LMG L Laser source receiver Test piece 20 mmφ x L100 mm furnace Perspective From the front Idea 1 Measurement System Test piece heater pyrometer 計測フロンティア研究部門 thermocouple 20 mmφ x L100 mm Laser microgage LMG receiver Laser sauce Front door heater Perspective From top 計測フロンティア研究部門 ここに 技あり halber Punkt External appearance of device 計測フロンティア研究部門 Spring gage LMG LMG Front door LMG: TOE D5-1505Ⅱ-HS Furnace inside Pass slit for laser beam 計測フロンティア研究部門 Detector rod Back heater Pass slit for laser beam Support tube Furnace inside 計測フロンティア研究部門 Detector rod Support tube Test piece (Φ20 mm x 100 mm) 12 Reference material : IGS743 計測フロンティア研究部門 Heat Rate: 10℃/min 8.0 Data from spring gage Elongation / mm 6.0 4.0 1400℃ 2.0 0.0 0 500 1000 1500 Temperature / oC Reference 2000 data 2500 13 Reference material : IGS743 8.0 Contact method Data from spring gage 6.0 Elongation / mm 計測フロンティア研究部門 4.0 Base line 2.0 0.0 0 500 1000 1500 Temperature / oC Reference 2000 data 2500 14 Idea 2 Laser beam & Support tube test piece 計測フロンティア研究部門 Pass slit for laser beam in thermal insulator Laser beam Pass slit for laser beam Idea 2 Signal of LMG receiver Laser beams reached to receiver 計測フロンティア研究部門 計測フロンティア研究部門 @2400℃ Laser source Receiver Elongation measurement by LMG 計測フロンティア研究部門 CIP:IGS743 Elongation (mm) 1.5 Red: measured (heating) 1.0 Blue: measured (cooling) Reference data 0.5 0.0 0 500 1000 1500 Temperature (℃) 2000 2500 Good Job! Gut gemacht! 計測フロンティア研究部門 1.8 7.0E-06 CIP:IGS743 1.6 6.0E-06 5.0E-06 1.2 CTE (right scale) 1.0 0.8 contact non-contact (LMG) 0.6 Thermal expansion (left scale) 0.4 4.0E-06 3.0E-06 2.0E-06 0.2 1.0E-06 0.0 -0.2 0 500 1000 1500 Temperature / ℃ 2000 0.0E+00 2500 CTE / K-1 Thermal Expansion / % 1.4 CIP & Nipple 1.7 7.0E-06 1.5 CIP 6.0E-06 1.3 5.0E-06 CTE (right scale) 1.1 4.0E-06 0.9 0.7 nipple TE (left scale) 0.5 3.0E-06 2.0E-06 1.0E-06 0.3 0.1 0.0E+00 -0.1 -1.0E-06 2500 0 500 1000 1500 Temperature / ℃ 2000 CTE / K-1 Thermal Expansion / % 計測フロンティア研究部門 CIP & Nipple 計測フロンティア研究部門 1.7 7.0E-06 CIP 6.0E-06 1.3 5.0E-06 CTE (right scale) 1.1 4.0E-06 0.9 0.7 nipple TE (left scale) 0.5 3.0E-06 2.0E-06 1.0E-06 0.3 0.1 0.0E+00 -0.1 -1.0E-06 2500 0 500 1000 1500 Temperature / ℃ 2000 CTE / K-1 Thermal Expansion / % 1.5 Sample Dimension Change of “carbonized計測フロンティア研究部門 block” Linear thermal expansion (%) 0.5 0.0 heating -0.5 1100℃ -1.0 -1.5 -2.0 1600℃ -2.5 cooling -3.0 measured by LMG -3.5 -4.0 0 500 1000 1500 Temperature (oC) 2000 2500 Summary The development the measurement device of thermal expansion of artificial graphite at high temperature can be succeeded using isotropic graphite, as heater, measurement jigs and the reference materials Not only contact method, but also non-contact method for the measurement of thermal expansion can be adapted in the device. By introducing the non-contact method with LMG, accurate thermal expansion can be measured up to 2400 oC. Summary 2 CIP isotropic graphite has three times larger thermal expansion and CTE than Nipple electrode. In the case of Nipple electrode with strongly anisotropic orientation, negative thermal expansion at the temperature between 200~300 oC was observed with LMG. By the developed device, thermal shrinkage of carbonized block can be observed at high temperature above 1100 oC. Two steps of shrinkage behavior against temperature was observed. Thank you very much for your attention Good Job! Gut gemacht!
© Copyright 2025 ExpyDoc