scholarly journals Heat sensor for ventilation systems

2021 ◽  
Vol 18 (4) ◽  
pp. 100-104
Author(s):  
A. V. Patrin ◽  
◽  
T. S. Rogozhina ◽  
Keyword(s):  
Heat Treatment ◽  
Longitudinal Force ◽  
Experimental Results ◽  
Sensor Design ◽  
Nylon Thread ◽  
Deformation Properties ◽  
Heat Sensor ◽  
Ventilation Systems

Based on the experimental results, the authors propose a heat sensor design intended for maintaining the temperature in a greenhouse or a premise, the principle of operation of such device being based on the fiber changing the length as affected by the temperature. There is described a method for manufacturing a thermal drive fiber from a nylon thread and a method of heat treatment to improve its deformation properties. The dependence of the longitudinal force of the thermal drive fiber on the temperature has been obtained.

Surface Oxidation Behaviour of Cubic BN Powders

2014 ◽  
Vol 602-603 ◽  
pp. 544-547
Author(s):  
Xin Yan Yue ◽  
Yue Zhang ◽  
Jian Jun Wang ◽  
Wei Wang ◽  
Hong Qiang Ru
Keyword(s):  
Heat Treatment ◽  
Surface Oxidation ◽  
Mass Gain ◽  
Oxidation Behaviour ◽  
Experimental Results ◽  
Oxidation Temperature ◽  
Oxidation Reactions ◽  
Oxidation Treatment ◽  
Treatment Processes

In order to improve the sinterability of the cBN, surface oxidation treatment was conducted to form a B2O3 film on the surface of the cBN powders. The cBN powders (d50 = 7.5 μm) were used as original powders. The heat treatment processes were 500, 800, 900, 950, 980 and 1000 °C holding for 30 minutes, respectively. The oxidation reactions which probably happened were calculated based on the thermodynamics. The experimental results showed that the oxidation starting temperature of cBN powders was higher than 800 °C. The higher the oxidation temperature, the greater the mass gain of the cBN powders.

Influence of Residual Stress on the Thermal Expansion Behavior of Electroformed Nickel Layers

2013 ◽  
Vol 662 ◽  
pp. 511-514
Author(s):  
Yi Chun Liu ◽  
Jia Min Zhang ◽  
Jian Hong Yi
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Thermal Expansion ◽  
Theoretical Analysis ◽  
Subsequent Heat Treatment ◽  
Experimental Results ◽  
Thermal Expansion Behavior ◽  
Expansion Behavior ◽  
Electroformed Nickel ◽  
The Relationship

Nickel layers with tensile or pressure residual stress were prepared by electroforming technique from two kinds of electrolyte. Subsequent heat treatment was adopted to get the stress released. The coefficients of thermal expansion (CTEs) were measured with a thermal dilatometer and the relationship between residual stress and the measured CTEs was revealed both from experimental results and theoretical analysis.

Predictive Kinetics-based Model for Shock-activated Reaction Synthesis of Ti3SiC2

2005 ◽  
Vol 20 (6) ◽  
pp. 1476-1484
Author(s):  
Jennifer L. Jordan ◽  
John A. Pelesko ◽  
Naresh N. Thadhani
Keyword(s):  
Heat Treatment ◽  
Activation Energy ◽  
Steady State ◽  
Predictive Model ◽  
Heat Dissipation ◽  
Experimental Results ◽  
Reaction Synthesis ◽  
Synthesis Conditions ◽  
Type Reaction ◽  
Activated State

A kinetics model based on mass and heat transport has been developed for Ti3SiC2 formation via shock-activated reaction synthesis of powder precursors. The model allows prediction of heat treatment conditions under which an otherwise steady-state reaction is taken over by a “run-away” combustion-type reaction during post-shock reaction synthesis of Ti3SiC2. Shock compression of Ti, SiC, and graphite precursors generates a densely packed highly activated state of reactants, which lowers the activation energy and results in an increased rate of formation of Ti3SiC2 at a lower temperature and in shorter times. The predictive model correlated with experimental results of fraction reacted as a function of time at heat-treatment temperatures of 1400 and 1600 °C illustrates an increased rate of reaction due to lowering activation energy, which also results in the reaction at 1600 °C being taken over by a “run-away” combustion-type reaction, as the rate of heat release due to reaction exceeds the rate of heat dissipation through the compact. Correlation of the model with experimental results illustrates that the predictive model can be used to optimize reaction synthesis conditions in shock-densified compacts of Ti3SiC2-forming powder precursors, to better understand the processes leading to a steady-state reaction being taken over by the combustion mode.

A Brief Review on Validation for Heat Treatment Simulation

2021 ◽  
Author(s):  
Kyozo Arimoto
Keyword(s):  
Heat Treatment ◽  
Measurement Data ◽  
Strain Analysis ◽  
Experimental Results ◽  
Stress Distributions ◽  
Simulation Functions ◽  
Basic Functions ◽  
Hardness Prediction ◽  
Quenched Steel ◽  
Complex Phenomena

Abstract Heat treatment simulation has progressed to the stage where several commercial software are available. Validations of simulation functions using experimental results contributed to this realization. Organizing information on the validations may be effective for maintaining the functions and educating users about the nature of the phenomena. For this reason, the author here briefly reviews mainly his validation cases. Since experiments using specimens having relatively simple shapes can reveal the essence of complex phenomena, the results have been used in the validations. When the basic functions such as heat transfer, phase transformation, latent heat, and hardness prediction were comprehensively validated in the early stages of software development, the author used experimental results of the inverse hardening in quenched steel cylinders. After that, his validations of the software at the stage where adding stress and strain analysis functions, used effectively measurement data of length and diameter changes, and residual stress distributions in normally quenched steel cylinders. While, it was also worth to validate curving in long specimens cooled unevenly, which included a case of specimens with a similar cross-section to the Japanese sword. In addition, the author validated distortions and residual stresses in carburized and quenched, induction hardened, and also nitrided specimens.

Fluidized bed heat treatment of aluminum cast components

2004 ◽  
Vol 120 ◽  
pp. 555-562
Author(s):  
D. Apelian ◽  
S. K. Chaudhury
Keyword(s):  
Heat Treatment ◽  
Fluidized Bed ◽  
Processing Time ◽  
Reaction Times ◽  
Experimental Results ◽  
Fluidized Bed Reactors ◽  
The Past ◽  
Conventional Furnace ◽  
Time Required ◽  
Solutionizing Time

Heat Treatment and post casting treatments of cast components has always been an important step in the control of microstructure, and resultant properties. In the past, the solutionizing, quenching and ageing process steps may have “required” in total over 20 hours of processing time. With the advent of fluidized bed reactors (FB), processing time has been dramatically reduced. For example, instead of 8-10 hours solutionizing time in a conventional furnace, the time required in FB is less than an hour. Experiments with Al-Si-Mg alloy, (both modified with Sr, and unmodified) were performed, having different diffusion distances (different DAS), and for different reaction times and temperatures. Both the model and the experimental results are presented and discussed.

scholarly journals ESTUDO COMPARATIVO ENTRE O FIO DE NAILON E A LINHA DE PESCA (POLIAMIDA) E A SUA APLICABILIDADE COMO FIO CIRÚRGICO

1999 ◽  
Vol 4 (1) ◽  
Author(s):  
SHEILA CANEVESE RAHAL ◽  
MANOEL ÁLVARO GUIMARÃES ◽  
JOSÉ VICENTE FORTES ◽  
HÉLIO LANGONI ◽  
PEDRO HELIO LUCCHIARI
Keyword(s):  
Adverse Effect ◽  
Comparative Study ◽  
Physical Properties ◽  
Group Iv ◽  
Experimental Results ◽  
Control Group ◽  
Group Iii ◽  
Nylon Thread ◽  
Group I ◽  
Mucous Membranes

"Linhas de pesca"* em diâmetros de 0,15mm; 0,20mm; 0,25mm; 0,30mm foram divididas em quatro grupos, contendo dez amostras de cada diâmetro: grupo I - controle; grupo II - linhas colocadas em frasco com pastilhas de formalina; grupo III - um ciclo de autoclavagem (30 minutos à 121 C, seguido por 10 minutos de secagem à 37 C em estufa); grupo IV - dois ciclos de autoclavagens. Foram avaliadas quanto: comprimento, calibre, resistência no nó e alongamento. Comparativamente foram examinados fios de náilon cirúrgico nas numerações 0, 1-0, 2-0, 3-0, 4-0 e 5-0 (10 amostras de cada um). Pelos resultados da análise estastística, verificou-se que a esterilização pelo calor úmido exerceu um efeito adverso na resistência da "linha de pesca". Por outro lado não houve diferenças na resistência, calibre e alongamento da "linha de pesca" entre o primeiro e segundo ciclo de autoclavagem. As “linhas” mantidas em pastilhas de formalina mantiveram na sua maioria suas características originais de resistência, comprimento, diâmetro e alongamento quando comparada ao grupo controle, entretanto, cabe lembrar que o formaldeído é considerado irritante para pele e membrana mucosa. Foi possível concluir que a "linha de pesca" apresenta características semelhantes ao fio cirúrgico, podendo ser mantida em pastilhas de formalina ou esterilizada em autoclave, lembrando que a autoclavagem altera algumas de suas propriedades físicas. Abstract A comparative study has been carried out between fishing lines and nylon thread in regard to their applicability as surgical thread. Four groups of 10 fishing lines in each of the following diameters = 0.15, 0.20, 0.25 and 0.30 mm = were subjected to the following treatments: group I, control; group II sterilized with formalin tablets; group III, autoclaved 30 minutes at 121oC; group IV, autoclaved twice 30 minutes at 121oC. The following parameters were then considered: length, caliber, resistance at the knot, and elongation. Ten samples of each surgical 0, 1.0, 2.0, 3.0, 4.0 and 5.0 nylon threads were used in comparatively similar experiments as the ones carried out with the fishing lines. According to the statistical analyses of the experimental results, it has been found that the sterilization by means of the humid heat exerts an adverse effect on the resistance of the fishing line. However, no differences were found between the effect displayed by two cycles sterilization compared with the fishing lines subjected to only one cycle. The threads maintained in formalin kept the majority of their original properties of resistance, length, diameter and elongation when compared with the control group. It is known, however that formaldehyde is an irritant chemical towards the skin and the mucous membranes. It was possible to conclude: a. fishing lines display characteristics similar to that ones of the nylon surgical thread; b. they can be maintained in formalin solution; c. autoclave sterilization alters some of their physical properties.

Machine Design for Multiscale Nitinol Annealment Process and End Product Performance Analysis

2020 ◽  
Author(s):  
Amanda Skalitzky ◽  
Stuart Coats ◽  
Ramsis Farag ◽  
Austin Gurley ◽  
David Beale
Keyword(s):  
Heat Treatment ◽  
Treatment Process ◽  
Heat Treating ◽  
Experimental Results ◽  
Heat Treatment Process ◽  
Scanning Calorimetry ◽  
Niti Wire ◽  
Annealing Temperatures ◽  
Conventional Heat Treatment ◽  
Post Production

Abstract The functional properties of Nitinol (NiTi) are set by composition, production process, and post-production heat treatment and cold working. Post-production heat treating is dependent on two main parameters: anneal temperature and aging time. Most heat-treating processes performed by researchers generally consist of simple temperature soaks at specified aging times. However, there are drawbacks to this method. More complex heat treatments can result in performance improvements, but they are difficult to implement and often proprietary to manufacturers and therefore not widely used by researchers. By designing a Continuously-Fed heat treatment System (CFS), this work demystifies this complex heat-treatment process by rapidly heat-treating NiTi wire samples across a range of annealing temperatures, soak times, and tensions with little human intervention. This automated process ensures samples are created in a consistent manner and results in a much more consistent end-product when compared to conventional heat-treating methods. Using the CFS, a gamut of samples with varying annealing temperatures (400–550°C) and aging times (1–3 minutes) were created with 0.25mm diameter high-temperature actuator wire initially in the ‘as-drawn’ condition. Differential Scanning Calorimetry (DSC) analysis was performed to determine how the transition temperature(s) change with the various heat-treating parameters and the mechanical properties of the wire were determined utilizing a tensile test. The experimental results demonstrate the benefits of the CFS and are compared to those of a more conventional heat treatment process. Experimental results show that high-performance Nitinol actuator behavior can consistently be achieved using the CFS. Optimal heat treatment processes can be determined quickly experimentally.

scholarly journals Analysis on three typical abnormal microstructures of overhead power line suspension clamps

2020 ◽  
Vol 165 ◽  
pp. 06029
Author(s):  
Weike Liu ◽  
Mengbao Zhou ◽  
Jiarui Hu ◽  
Songqi Wu ◽  
Xianhui Cao ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Hardness Measurement ◽  
Power Line ◽  
Experimental Results ◽  
Flake Graphite ◽  
Quality Inspection ◽  
X Ray ◽  
Metallographic Observation ◽  
Annealing Heat Treatment ◽  
Overhead Power Line

This article lists three typical abnormal microstructures of overhead power line suspension clamps, including inclusion, flake graphite and cementite network. A series of tests including macro check, hardness measurement, composition tests, Energy-dispersive x-ray analysis and metallographic observation have been carried out. The experimental results showed that the causes of abnormal microstructures mainly include: high content of impurities, flake graphite blank and unfulfilled annealing heat treatment. It is suggested to strengthen the supervision on suspension clamps before using, and focus on the quality inspection of metallographic structure and composition.

Strength-Deformation Properties of Fine-Grained Fibre-Reinforced Concretes

2013 ◽  
Vol 43 (3) ◽  
pp. 77-86
Author(s):  
M. Mironova ◽  
V. Naidenov
Keyword(s):  
Mechanical Properties ◽  
Residual Strength ◽  
Experimental Results ◽  
Fibre Reinforcement ◽  
Standard Laboratory ◽  
Basic Character ◽  
Laboratory Environment ◽  
Fine Grained ◽  
Hybrid Fibre ◽  
Deformation Properties

Abstract The main strength-deformation properties of fine-grained fiber-reinforced concretes with different type and quantity of fibres, used as repair overlays, are discussed. The results of mechanical properties of experimental compositions are obtained and generalized for two basis ages and standard laboratory environment. The experimental results are mathematical processed using MATLAB procedure. The basic character- istics - residual strength, toughness indexes and residual strength factors are obtained as a function of type as well as quantity of the hybrid fibre- reinforcement.

Fabrication of Bi-2223 Powders Using Sol-Gel Method

2011 ◽  
Vol 412 ◽  
pp. 125-128 ◽  
Author(s):  
Ming Ya Li ◽  
Xiao Yan Wang ◽  
Cheng Li Ye ◽  
Feng Lin Xue
Keyword(s):  
Heat Treatment ◽  
Sol Gel ◽  
Chelating Agent ◽  
Experimental Results ◽  
Main Phase ◽  
Gel Method ◽  
Sol Gel Method ◽  
Dwelling Time ◽  
Metal Nitrates ◽  
Gel Technique

The Bi-2223 powders were fabricated by the sol-gel technique. Metal nitrates were used as starting materials, and ethylenediamineteracetic acid was used as chelating agent. The solution was heated until it turns to gel. Then the organic was removed at a temperature of 240°C, and the nitrite was removed at 500°C. The powder was calcined at different temperature, varying the dwelling time. Experimental results show that the main phase of samples after heat treatment is Bi-2212 phase.

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