scholarly journals The influence of technological parameters on the hygroscopic properties of textiles

2021 ◽  
Author(s):  
E. V. Endiiarova ◽  
A. A. Osipov ◽  
S. E. Alexandrov
Keyword(s):  
Heat Treatment ◽  
Water Absorption ◽  
Aluminum Chloride ◽  
Chloride Solution ◽  
Soap Solution ◽  
Treatment Time ◽  
Solution Temperature ◽  
Capillary Absorption ◽  
Sample Treatment ◽  
Hygroscopic Properties

Abstract In this paper the method of wet chemistry used for hydrophobization of coarse calico surface was described. It was found that hydrophobicity of coarse calico surface is achieved by the formation of aluminum oxide on the surface. The effect of soap solution temperature, aluminum chloride solution concentration, sample treatment time in aluminum chloride solution and heat treatment temperature on water absorption, contact angle, capillary absorption and calico moisture content was studied. The dependences of gyroscopic properties on the process parameters were obtained. Capillary absorption and water absorption of the test samples increased with increasing concentration of aluminum chloride solution. An increase in the processing time of coarse calico samples in an aluminum chloride solution of lead to a decrease in the hydrophobicity of the samples. The characters of the dependences of hygroscopic properties on the temperature of heat treatment and the temperature of the soap solution are similar.

scholarly journals Selection of optimal solution heat treatment of the casting cylinder heads

2018 ◽  
Vol 157 ◽  
pp. 02053 ◽  
Author(s):  
Eva Tillová ◽  
Mária Chalupová ◽  
Lenka Kuchariková ◽  
Juraj Belan ◽  
Denisa Závodská
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Solution Heat Treatment ◽  
Treatment Time ◽  
Crack Nucleation ◽  
Particle Density ◽  
Solution Treatment ◽  
Optimal Solution ◽  
Solution Temperature ◽  
Selection Of

The effect of solution treatment on mechanical properties (UTS, elongation, Brinell hardness) and microstructure (Si-morphology and Si-size) of an aluminium alloy (A356) used for casting cylinder heads was studied. The tests were carried out with specimens machined from the bulkheads of V8 engine blocks cast by the low pressure process. The samples were tested in as-cast and T6 heat treating conditions (solution heat treatment at 530°C with different time - 2, 3, 4, 5, 6, 7 hours, quenching in water at 20°C and precipitation hardened for 4 hour at 160°C). The results show that used heat treatment improves mechanical properties of the cylinder head casts. Tensile strength and hardness of specimens increase with solution treatment time. The hardness is a reflection of solution strengthening and silicon particle distribution in matrix. Solution temperature 530°C and 5 hours solution time is appropriate to obtain better morphology and distribution of Si particles in microstructure. Prolonged solution treatment (more than 5 hours) leads to a coarsening of the Si particles, while the numerical Si density decreases. As the particle density decreases, a fewer number of sites are available for crack nucleation, and hence, the fracture properties are improved. The data obtained from this study will be used to improve process control, and to help the selection of heat treatment of the casting for future products.

Changes in cell wall components and hygroscopic properties of Pinus radiata caused by heat treatment

2021 ◽  
Author(s):  
Alberto García-Iruela ◽  
Luis García Esteban ◽  
Francisco García Fernández ◽  
Paloma de Palacios ◽  
Alejandro B. Rodriguez-Navarro ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Cell Wall ◽  
Pinus Radiata ◽  
Cell Wall Components ◽  
Hygroscopic Properties ◽  
Wall Components

scholarly journals Influence of Rapid Heat Treatment on the Shrinkage and Strength of High-Performance Concrete

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4102
Author(s):  
Jan Stindt ◽  
Patrick Forman ◽  
Peter Mark
Keyword(s):  
Heat Treatment ◽  
High Performance ◽  
High Performance Concrete ◽  
Treatment Time ◽  
Precast Concrete ◽  
Concrete Strength ◽  
Shrinkage Strain ◽  
Temperature Treatment ◽  
Production Flow ◽  
Steel Fibres

Resource-efficient precast concrete elements can be produced using high-performance concrete (HPC). A heat treatment accelerates hardening and thus enables early stripping. To minimise damages to the concrete structure, treatment time and temperature are regulated. This leads to temperature treatment times of more than 24 h, what seems too long for quick serial production (flow production) of HPC. To overcome this shortcoming and to accelerate production speed, the heat treatment is started here immediately after concreting. This in turn influences the shrinkage behaviour and the concrete strength. Therefore, shrinkage is investigated on prisms made from HPC with and without steel fibres, as well as on short beams with reinforcement ratios of 1.8% and 3.1%. Furthermore, the flexural and compressive strengths of the prisms are measured directly after heating and later on after 28 d. The specimens are heat-treated between 1 and 24 h at 80 °C and a relative humidity of 60%. Specimens without heating serve for reference. The results show that the shrinkage strain is pronouncedly reduced with increasing temperature duration and rebar ratio. Moreover, the compressive and flexural strength decrease with decreasing temperature duration, whereby the loss of strength can be compensated by adding steel fibres.

scholarly journals Water Resistance and Creep Behavior of Heat-Treated Moso Bamboo Determined by the Stepped Isostress Method

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1264
Author(s):  
Teng-Chun Yang ◽  
Tung-Lin Wu ◽  
Chin-Hao Yeh
Keyword(s):  
Heat Treatment ◽  
Water Absorption ◽  
Creep Behavior ◽  
Heat Treatment Temperature ◽  
Water Resistance ◽  
Absorption Efficiency ◽  
Treatment Temperature ◽  
Moso Bamboo ◽  
Phyllostachys Pubescens ◽  
Heat Treated

The influence of heat treatment on the physico-mechanical properties, water resistance, and creep behavior of moso bamboo (Phyllostachys pubescens) was determined in this study. The results revealed that the density, moisture content, and flexural properties showed negative relationships with the heat treatment temperature, while an improvement in the dimensional stability (anti-swelling efficiency and anti-water absorption efficiency) of heat-treated samples was observed during water absorption tests. Additionally, the creep master curves of the untreated and heat-treated samples were successfully constructed using the stepped isostress method (SSM) at a series of elevated stresses. Furthermore, the SSM-predicted creep compliance curves fit well with the 90-day full-scale experimental data. When the heat treatment temperature increased to 180 °C, the degradation ratio of the creep resistance (rd) significantly increased over all periods. However, the rd of the tested bamboo decreased as the heat treatment temperature increased up to 220 °C.

The Effect of Aging Heat Treatment on the Microstructure and Mechanical Properties of 10Cr20Ni25Mo1.5NbN Austenitic Steel

2016 ◽  
Vol 35 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Zhiyuan Liang ◽  
Wanhua Sha ◽  
Qinxin Zhao ◽  
Chongbin Wang ◽  
Jianyong Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Heat Treatment ◽  
Austenitic Steel ◽  
Treatment Time ◽  
Aging Treatment ◽  
Secondary Phases ◽  
Aging Heat Treatment ◽  
Microstructure And Mechanical Properties ◽  
The Impact

AbstractThe effect of aging heat treatment on the microstructure and mechanical properties of 10Cr20Ni25Mo1.5NbN austenitic steel was investigated in this article. The microstructure was characterized by scanning electron microscopy, energy dispersive spectrometry and transmission electron microscopy. Results show that the microstructure of 10Cr20Ni25Mo1.5NbN austenitic is composed of austenite. This steel was strengthened by precipitates of secondary phases that were mainly M23C6 carbides and NbCrN nitrides. As aging treatment time increased, the tensile strength first rose (0–3,000 h) and then fell (3,000–5,000 h) due to the decrease of high density of dislocations. The impact absorbed energy decreased sharply, causing the sulfides to precipitate at the grain boundary. Therefore, the content of sulfur should be strictly controlled in the steelmaking process.

scholarly journals The development of low-temperature heat-treatable high-pressure die-cast Al–Mg–Fe–Mn alloys with Zn

2021 ◽  
Author(s):  
Xiangzhen Zhu ◽  
Fuchu Liu ◽  
Shihao Wang ◽  
Shouxun Ji
Keyword(s):  
Heat Treatment ◽  
Low Temperature ◽  
Mechanical Test ◽  
Equilibrium Phase ◽  
Solution Temperature ◽  
Tem Analysis ◽  
Die Cast ◽  
Zn Concentration ◽  
Temperature Heat ◽  
Cast Alloys

AbstractIn the present work, a novel low-temperature heat-treatable recycled die-cast Al–Mg alloy was developed by adding Zn into non-heat-treatable Al–5Mg–1.5Fe–0.5Mn alloy. The results showed that Zn additions resulted in the formation of equilibrium phase T-Mg32(Al, Zn)49 under as-cast condition, which can be dissolved into the α-Al matrix at a relatively low solution temperature (430 °C) and thus set the base for the low-temperature heat treatment. The mechanical test results indicated that Zn additions had a smooth liner improvement in the strength of all as-cast alloys and T6-state alloys with 1% and 2% Zn as its concentration increased but resulted in a sharp improvement on the strength of T6-state alloy when Zn concentration increased from 2 to 3%. TEM analysis revealed that the precipitate in T6-state Al–5Mg–1.5Fe–0.5Mn–3Zn alloy is η′ phase, rather than the widely reported T″ or T′ phase in other Al–Mg–Zn alloys with approximately same Mg and Zn concentrations. After the optimized low-temperature T6 heat treatment (solution at 430 °C for 60 min and ageing at 120 °C for 16 h), the Al–5Mg–1.5Fe–0.5Mn–3Zn alloy exhibits the yield strength of 321 MPa, ultimate tensile strength of 445 MPa and elongation of 6.2%.

scholarly journals Enhanced aging kinetics in Al-Mg-Si alloys by up-quenching

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Florian Schmid ◽  
Philip Dumitraschkewitz ◽  
Thomas Kremmer ◽  
Peter J. Uggowitzer ◽  
Ramona Tosone ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Treatment Time ◽  
Cluster Formation ◽  
High Strength ◽  
Second Phase ◽  
Second Phase Particles ◽  
Negative Effect ◽  
High Elongation ◽  
Aging Kinetics ◽  
Complex Parts

AbstractPrecipitation-hardened aluminium alloys typically obtain their strength by forming second-phase particles, which, however, often have a negative effect on formability. To enable both lightweight construction and forming of complex parts such as body panels, high strength and formability are required simultaneously. Cluster hardening is a promising approach to achieve this. Here, we show that short thermal spikes, denoted as up-quenching, increase aging kinetics, which we attribute to the repeated process of vacancies being formed at high temperatures and retained when cooled to lower temperatures. Combined with further heat treatment, the up-quenching process promotes rapid and extensive cluster formation in Al-Mg-Si alloys, which in turn generates significant strengthening at industrially relevant heat treatment time scales. The high elongation values also observed are attributed to reduced solute depleted zones along grain boundaries.

scholarly journals Effects of Different Solid Solution Temperatures on Microstructure and Mechanical Properties of the AA7075 Alloy After T6 Heat Treatment

2019 ◽  
Vol 38 (2019) ◽  
pp. 892-896 ◽  
Author(s):  
Süleyman Tekeli ◽  
Ijlal Simsek ◽  
Dogan Simsek ◽  
Dursun Ozyurek
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Solid Solution ◽  
Tensile Strength ◽  
Tensile Tests ◽  
Solution Temperature ◽  
T6 Heat Treatment ◽  
Microstructure And Mechanical Properties ◽  
Different Temperatures

AbstractIn this study, the effect of solid solution temperature on microstructure and mechanical properties of the AA7075 alloy after T6 heat treatment was investigated. Following solid solution at five different temperatures for 2 hours, the AA7075 alloy was quenched and then artificially aged at 120∘C for 24 hours. Hardness measurements, microstructure examinations (SEM+EDS, XRD) and tensile tests were carried out for the alloys. The results showed that the increased solid solution temperature led to formation of precipitates in the microstructures and thus caused higher hardness and tensile strength.

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