3D-Shaping of Ceramic Tapes to Manufacture a High-Temperature Miniaturized Furnace

2015 ◽  
Vol 2015 (CICMT) ◽  
pp. 000282-000286
Author(s):  
Jaroslaw Kita ◽  
Annica Brandenburg ◽  
Irina Sudina ◽  
Ralf Moos
Keyword(s):  
High Temperature ◽  
Temperature Distribution ◽  
Finite Elements ◽  
Design Process ◽  
Gas Sensors ◽  
Furnace Chamber ◽  
Finite Elements Analysis ◽  
Fast Heating ◽  
Hexagonal Form ◽  
Critical Materials

This contribution shows results of 3D-shaping experiments of ceramic tapes. The structures were made by wrapping structured tapes around a hexagonal alumina rod. After lamination, the rod was removed and the structure was finally fired, similarly as reported in [1]. One out of many possible applications of such structures is a miniaturized furnace for sintering of critical materials, which could contaminate expensive chamber furnaces, for tempering of single gas sensors, or for fast heating at controlled rate. While LTCC technology can be applied only up to 600–700 °C, application of HTCC tapes can extend temperature range to above 1000 °C. Therefore, 99.99% alumina tape (ESL 44007) was used. The here-shown miniaturized furnace has a hexagonal form. For a proper temperature distribution in the furnace chamber, the furnace was equipped with six platinum heaters that can be controlled independently. Finite Elements Analysis (FEM) supported the design process. The paper discusses manufacturing route, beginning with a design process supported by FEM through 3D-shaping by wrapping structured tapes around an alumina rod and finally firing and functionality tests.

A SPLINES BASED METHOD FOR MODELING THE HUMAN HEAD FOR USE IN FINITE ELEMENTS ANALYSIS

2017 ◽  
Author(s):  
Daniel Ponce ◽  
Eduardo Szpoganicz ◽  
Leonardo Mejia Rincon ◽  
Ernesto Ponce Lopez
Keyword(s):  
Finite Elements ◽  
Human Head ◽  
Finite Elements Analysis

scholarly journals CO Detection Investigation at High Temperature by SiC MISFET Metal/Oxide Gas Sensors

Proceedings ◽  
2021 ◽  
Vol 56 (1) ◽  
pp. 41
Author(s):  
Lida Khajavizadeh ◽  
Anita Lloyd Spetz ◽  
Mike Andersson
Keyword(s):  
High Temperature ◽  
Gas Sensors ◽  
Elevated Temperatures ◽  
Long Term Stability ◽  
Stability Performance ◽  
Catalytic Metal ◽  
Co Detection ◽  
Effect Transistor ◽  
Metal Oxide Gas Sensors

In order to investigate the necessary device improvements for high-temperature CO sensing with SiC metal insulator semiconductor field effect transistor (MISFET)-based chemical gas sensors, devices employing, as the gas-sensitive gate contact, a film of co-deposited Pt/Al2O3 instead of the commonly used catalytic metal-based contacts were fabricated and characterized for CO detection at elevated temperatures and different CO and O2 levels. It can be concluded that the sensing mechanism at elevated temperatures correlates with oxygen removal from the sensor surface rather than the surface CO coverage as observed at lower temperatures. The long-term stability performance was also shown to be improved compared to that of previously studied devices.

scholarly journals Laboratory-Scale Processing and Performance Assessment of Ti–Ta High-Temperature Shape Memory Spring Actuators

2021 ◽  
Author(s):  
A. Paulsen ◽  
H. Dumlu ◽  
D. Piorunek ◽  
D. Langenkämper ◽  
J. Frenzel ◽  
...  
Keyword(s):  
High Temperature ◽  
Shape Memory ◽  
Detrimental Effect ◽  
Wire Drawing ◽  
Fast Heating ◽  
Heating And Cooling ◽  
Arc Melting ◽  
Ω Phase ◽  
And Performance

AbstractTi75Ta25 high-temperature shape memory alloys exhibit a number of features which make it difficult to use them as spring actuators. These include the high melting point of Ta (close to 3000 °C), the affinity of Ti to oxygen which leads to the formation of brittle α-case layers and the tendency to precipitate the ω-phase, which suppresses the martensitic transformation. The present work represents a case study which shows how one can overcome these issues and manufacture high quality Ti75Ta25 tensile spring actuators. The work focusses on processing (arc melting, arc welding, wire drawing, surface treatments and actuator spring geometry setting) and on cyclic actuator testing. It is shown how one can minimize the detrimental effect of ω-phase formation and ensure stable high-temperature actuation by fast heating and cooling and by intermediate rejuvenation anneals. The results are discussed on the basis of fundamental Ti–Ta metallurgy and in the light of Ni–Ti spring actuator performance.

Investigation Into Thermal Stress Characteristics of Pipe-in-Pipe Under High Temperature Condition

2018 ◽  
Author(s):  
Si-Hwa Jeong ◽  
Min-Gu Won ◽  
Nam-Su Huh ◽  
Yun-Jae Kim ◽  
Young-Jin Oh ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Stress ◽  
High Temperature ◽  
Temperature Distribution ◽  
Heat Transfer Analysis ◽  
Piping System ◽  
Curved Pipe ◽  
High Temperature Condition ◽  
Single Pipe ◽  
Radiation Conditions

In this paper, the thermal stress characteristics of the pipe-in-pipe (PIP) system under high temperature condition are analyzed. The PIP is a type of pipe applied in sodium-cooled faster reactor (SFR) and has a different geometry from a single pipe. In particular, under the high temperature condition of the SFR, the high thermal stress is generated due to the temperature gradient occurring between the inner pipe and outer pipe. To investigate the thermal stress characteristics, three cases are considered according to geometry of the support. The fully constrained support and intermediate support are considered for case 1 and 2, respectively. For case 3, both supports are applied to the actual curved pipe. The finite element (FE) analyses are performed in two steps for each case. Firstly, the heat transfer analysis is carried out considering the thermal conduction, convection and radiation conditions. From the heat transfer analysis, the temperature distribution results in the piping system are obtained. Secondly, the structural analysis is performed considering the temperature distribution results and boundary conditions. Finally, the effects of the geometric characteristics on the thermal stress in the PIP system are analyzed.

Research on Temperature Changes and Microstructure Evolution of Steel Target after the Penetration by Copper Jet

2011 ◽  
Vol 311-313 ◽  
pp. 953-956
Author(s):  
Hao Chen ◽  
Gang Tao
Keyword(s):  
Grain Size ◽  
High Temperature ◽  
Temperature Distribution ◽  
Microstructure Evolution ◽  
Deformation Zone ◽  
Superplastic Deformation ◽  
Theoretical Formula ◽  
Temperature Changes ◽  
Normal Deformation ◽  
Steel Target

In order to study dynamic response of metal, this paper makes use of theoretical formula to investigate changes of temperature and grain size on steel target after the penetration of copper jet based on data gathered from the experiments. Deformed target penetrated by copper jet could be divided into superplastic deformation zone and normal deformation zone according to the different microstructure. Temperature distribution of each deformation zones is in turn calculated by two constitutive equations. The results indicate that areas with high temperature concentrate on the narrow zone near the penetrated channel. Then, the calculation of grain size conforms to the observation. It is obviously proven that the method used in this paper is trustworthy for calculating the changes of temperature and grain size of target caused by penetration.

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