Crack Detection in Aircraft Structures

1956 ◽  
Vol 60 (551) ◽  
pp. 739-748 ◽  
Author(s):  
W. Deck
Keyword(s):  
Heat Treatment ◽  
Sheet Metal ◽  
Crack Detection ◽  
Raw Materials ◽  
Aircraft Maintenance ◽  
Aircraft Structures ◽  
Heat Treated

In Switzerland aircraft often have to take off and land in narrow mountain valleys where a strong, irregular wind is blowing. In these circumstances one faulty casting may cause failure of a control; or a small part, if insufficiently heat-treated, may fracture and result in the loss of the aircraft. For this reason, thorough inspection during production and careful maintenance of the aircraft are of prime importance. Control within the aircraft factory consists of inspection of the raw materials, such as bars, sheet metal, tubes, castings, forgings and so on; testing of the most important parts during manufacture to detect cracks and to control the heat treatment; and the final control of all parts, of components and of the whole aircraft. Maintenance inspection reveals cracks, corrosion and other defects of the most important parts of the aircraft.

scholarly journals Study on the Properties of Transparent Bamboo Prepared by Epoxy Resin Impregnation

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 863 ◽  
Author(s):  
Yan Wu ◽  
Yajing Wang ◽  
Feng Yang ◽  
Jing Wang ◽  
Xuehua Wang
Keyword(s):  
Heat Treatment ◽  
Tensile Strength ◽  
Visible Light ◽  
Epoxy Resin ◽  
Raw Materials ◽  
Light Transmittance ◽  
Advantages And Disadvantages ◽  
Heat Treated ◽  
Before And After ◽  
Different Parts

In this paper, Moso bamboo (Phyllostachys heterocycle) before and after heat treatment were used as raw materials to prepare transparent bamboo (TB). In an acidic environment, the lignin contained in the bamboo material was removed to obtain a bamboo template, and an epoxy resin similar to the cellulose refractive index was used for vacuum impregnation into the bamboo template to obtain a transparent bamboo material. The purpose of this study was to compare the physical and chemical properties of TB and original bamboo and the differences between TBs before and after heat treatment, taken from different parts of bamboo, in order to explore the performance advantages and disadvantages of TB as a new material. The Fourier transform infrared spectroscopy analysis (FTIR), scanning electron microscope testing (SEM), three elements analysis, light transmittance testing, and mechanical strength testing were used to study the molecular composition, microstructure, chemical composition, light transmittance, and tensile strength of the TB samples. The results showed that the lignin content of the delignified bamboo templates was greatly reduced. In addition, the SEM images showed that a large amount of epoxy resin (type E51 and type B210 curing agent) was covered on the cross-section surface and pores of the TB samples. The FTIR showed that the epoxy molecular groups appeared on the TB, and the delignified bamboo template and the resin had a good synergy effect. According to the light transmittance testing, the original bamboo samples hardly contained light transmittance under visible light. The transmittance of transparent inner bamboo (TIB) and transparent heat-treated inner bamboo (THIB) could reach about 11%, and the transmittance of transparent outer bamboo (TOB) and transparent heat-treated outer bamboo (THOB) was about 2%. The light transmittance had been significantly improved when compared with the original bamboo samples. The transmittances of the TB samples before and after heat treatment in different parts of bamboo were different. In the visible light irradiation range, the light transmittances of TB samples were as follows: TIB > THIB and THOB > TOB. Meanwhile, the tensile strength of TB was reduced, especially for TOB and THOB. In addition, TB has a wide range of raw materials, and the preparation process is environmentally friendly. It can be used for decorative materials in homes, buildings, etc., and has a great application potential.

The Through-Dyed Autoclaved Silicate Concretes with the Use of Thermally Activated Iron Ore Raw Materials Refinement Tailings

2018 ◽  
Vol 284 ◽  
pp. 1101-1106
Author(s):  
Irina V. Starostina
Keyword(s):  
Heat Treatment ◽  
Iron Oxides ◽  
Iron Ore ◽  
Raw Materials ◽  
Control Sample ◽  
Strength Properties ◽  
Synthesis Rate ◽  
Thermally Activated ◽  
Calcium Silicate Hydrates ◽  
Heat Treated

The iron ore raw materials refinement waste is not virtually used after the wet magnetic separation and is accumulated in special hydraulic constructions – tailing dumps. This work considers the opportunity of using the heat-treated tailings as loading pigments for through-dyed autoclaved silicate concretes production. The heat-treated tailings were added to the raw mix instead of quartz sand. The concrete samples of light-pink shades of color were obtained. It has been demonstrated that the activation processes, taking place at heat treatment of tailings, as well as the influence of iron oxides acting as a mineralizer at high temperatures, create the increased imperfection of the quartz component’s structure. This increases the synthesis rate of new formations – the low-basic calcium silicate hydrates – and increases the strength properties of the samples with optimal compositions by 70-75% as compared to the control sample.

Effect of Heat Treatment on the Crystal Structure of the Anodic Cerium Oxide Films

2017 ◽  
Vol 748 ◽  
pp. 12-16
Author(s):  
Xiao Zhen Liu ◽  
Yu Fan Ni ◽  
Xiao Zhou Liu ◽  
Le Tian Xia ◽  
Jie Chen ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Oxide Film ◽  
Crystal Structures ◽  
Cerium Oxide ◽  
Cerium Dioxide ◽  
Raw Materials ◽  
Oxide Films ◽  
Treatment Temperature ◽  
Heat Treated ◽  
Dioxide Film

The cerium dioxide films were prepared with cerium foils as raw materials by anodization in Na2C2O4-NH3∙H2O-H2O-(CH2OH)2 electrolyte. The anodic cerium oxide films were heat treated in 100~400°C and 0.5~2.5h, respectively. The heat treated anodic cerium oxide films were characterized with X-ray diffraction (XRD). The heat treated anodic cerium oxide film at 100°C is semi crystalline film. The heat treated anodic cerium oxide film at 200°C, 300°C, 350°C, 400°C, respectively for 2h, is the cerium dioxide film respectively, and has a structure of cubic fluorite respectively. The crystal structures of the cerium dioxide films become more complete with the increase of heat treatment temperature in 200 ~ 400 °C. The heat treated anodic cerium oxide film at 400°C for 0.5h, 1h, 1.5h, 2.5h, respectively, is the cerium dioxide film respectively, and has a structure of cubic fluorite respectively. The crystal structures of the cerium dioxide films become more complete with the increase of heat treatment times in 0.5h ~ 2.5h.

scholarly journals Precision of laboratory methods based on protein solubility in quality control of heat treated feedstuffs

2012 ◽  
Vol 66 (1) ◽  
pp. 53-57
Author(s):  
Dragan Palic ◽  
Liesl Morey ◽  
Kedibone Modika ◽  
Bojana Kokic ◽  
Olivera Djuragic ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Quality Control ◽  
Raw Materials ◽  
Protein Solubility ◽  
Heat Processing ◽  
Laboratory Methods ◽  
Nutritional Factors ◽  
Heat Treated ◽  
Laboratory Procedures ◽  
Reproducibility Limit

Some of feedstuffs used as raw materials in feed industry contain anti-nutritional factors that negatively influence their quality. One of them is soybean, which is, prior to oil extraction, referred to as full-fat soybean (FFSB). Anti-nutritional factors in raw FFSB can be destroyed by moderate heating, but both over- and under heat processing limits the availability of soybean amino acids. Among laboratory procedures that are available for assessing the degree of FFSB heat treatment, two methods, i.e. Protein dispersibility index (PDI) and protein solubility in potassium hydroxide (PSKOH), are based on protein solubility, which was claimed to be the most reliable indicator of the degree of FFSB heat treatment. This paper presents the results of an inter-laboratory study conducted to establish precision of the PDI and PSKOH methods by determining their reproducibility limits. Five samples of FFSB were heat-treated at temperatures between 110 and 164 ?C and analyzed by six laboratories for PDI and PSKOH. Established reproducibility limit for PDI method of 8.87 index units found in this study appeared to be too wide, indicating a low precision of this method. PSKOH method produced very good reproducibility limit of 8.56% and could be recommended as a preferred method for FFSB quality control in feed laboratories.

Synthesis of Ti2AlC/Al2O3 Nanocomposites by High Energy Milling and Heat Treatment

2010 ◽  
Vol 658 ◽  
pp. 89-92 ◽  
Author(s):  
Jian Feng Zhu ◽  
Guo Quan Qi ◽  
Hai Bo Yang ◽  
Fen Wang
Keyword(s):  
Heat Treatment ◽  
Ultrafine Particles ◽  
Raw Materials ◽  
Equilibrium Phase ◽  
High Energy ◽  
High Energy Milling ◽  
Intermediate Phases ◽  
Heat Treated ◽  
Vacuum Atmosphere ◽  
Formation And Evolution

Ti2AlC/Al2O3 nanocomposites were synthesized by high energy milling with Ti, C, Al and TiO2 as initial materials. The formation and evolution of phases in high energy milling and following heat treatment were investigated by X-ray diffractometer (XRD). The results show that the raw materials of Ti, C, Al and TiO2 were pulverized to ultrafine particles, and some of them transformed to amorphous phase. When the as-milled powders were heat treated in vacuum atmosphere, TiC was firstly produced and released large amount of reactive heat, which resulted in the reaction between Ti and Al to produce intermediate phases of the TixAly (TiAl3, TiAl, and Ti3Al) intermetallics. The reaction between Al and TiO2 produced Al2O3 phase. The TixAly intermetallics and the residual Ti and Al transformed to TiAl equilibrium phase. Finally, the TiAl intermetallics and the TiC reacted to yield Ti2AlC, which produced Ti2AlC/Al2O3 nanocomposite together with the former in-situ formed Al2O3.

The Effect of Heat Treatment on Fe2+/Fe3+ Ratio in Soda-Lime Silicate Glass

2015 ◽  
Vol 659 ◽  
pp. 194-198 ◽  
Author(s):  
Ekarat Meechoowas ◽  
Suwipa Poosrisoma ◽  
Parida Jampeerung ◽  
Tepiwan Jitwatcharakomol
Keyword(s):  
Heat Treatment ◽  
Iron Oxide ◽  
Silicate Glass ◽  
Redox Reaction ◽  
Raw Materials ◽  
Soda Lime ◽  
Annealing Process ◽  
Heat Treated ◽  
Vis Spectroscopy ◽  
Soda Lime Silicate Glass

The redox reaction of a tableware soda-lime silicate glass contained with 0.04 - 1.00 wt% of iron oxide is investigated by UV-Vis spectroscopy. The quality and purity of raw materials, especially sand is required to control the amount of iron oxide as low as possible. Normally tableware glass contains small amount of iron oxide (0.01 - 0.04 wt%) and iron effect (green color) is controlled by adding decolorizing agent. The heat treatment around transition temperature is another method to decolorize iron by redox reaction control. It is believed that the reaction of iron oxide Fe2+(green) « Fe3+(yellow) still occurs in annealing process. In this study, the glasses were prepared by melting in the platinum crucibles. After annealing, they are cut into four pieces and heated at 550 560 570 and 580°C with different times. The results of the transmittance showed no significantly change but the color in CIE L*a*b* system of glasses heat treated at 550 and 560 °C slightly change into whiter shade. According to the result of calculated Fe2+/Fe3+ ratio, the ratio of these glasses were decreased by 5 and 2.5 % respectively. On the contrary, the redox ratio of glass heated at 580 °C increased, due to Fe3+to Fe2+ and the color changed into green. The results proved the kinetic of the redox reaction of Fe2O3 and the possibility to use annealing process as another tool to control flint color of glass.

Heat Treatment

2020 ◽  
Author(s):  
Patrick Schmidt
Keyword(s):  
Heat Treatment ◽  
Raw Materials ◽  
Middle Stone Age ◽  
Raw Material ◽  
Coarse Grained ◽  
Fine Grained ◽  
Heat Treated ◽  
Silica Rocks ◽  
People First ◽  
North And South America

In archaeology, heat treatment is the intentional transformation of stone (normally sedimentary silica rocks) by fire to produce materials with improved fracture properties. It has been documented on all continents, from the Africa Middle Stone Age up to subrecent times. It was an important part of the Mediterranean Neolithic and it sporadically appeared in the Paleolithc and Mesolithic of Asia and Europe. It may have been part of the knowledge of people first colonizing North and South America, and it played an important role for toolmaking in the Australian Prehistory. In all these contexts, heat treatment was normally used to improve the quality of stone raw materials for tool knapping; especially its association with pressure flaking has been highlighted, but a few examples also document the quest of making tools with improved qualities (sharper cutting edges) and intentional segmentation of large blocks of raw material to produce smaller, better-usable modules (fire fracturing). Two categories of silica rocks were most often heat-treated throughout prehistory: relatively fine-grained marine chert or flint and more coarse-grained continental silcrete. The finding of stone heat treatment in archaeological contexts opens up several research questions on its role for toolmaking, its cognitive and social implications, and the investment it required. Important venues for research are, for example: Why did people heat-treat stone? What happens to stones when heated? How can heating be recognized? By what technical means were stones heated? Which cost did heat treatment represent for its instigators? Answering these questions allows light to be shed on archaeologically relevant processes like innovation, reinvention, convergence, or the advent of complexity. The methods needed to produce these answers, however, often stem from other fields such as physics, chemistry, mineralogy, or material sciences.

Effect of a Complex Heat Treatment on the Structure of 300M Steel

1981 ◽  
Vol 39 ◽  
pp. 312-313
Author(s):  
R. Padmanabhan ◽  
W. E. Wood
Keyword(s):  
Heat Treatment ◽  
Metal Carbides ◽  
Austenite Grain Size ◽  
300M Steel ◽  
Heat Treated ◽  
Strain Fracture ◽  
Prior Austenite Grain Size ◽  
Short Time ◽  
Final Tempering ◽  
Similar Yield

Intermediate high temperature tempering prior to subsequent reaustenitization has been shown to double the plane strain fracture toughness as compared to conventionally heat treated UHSLA steels, at similar yield strength levels. The precipitation (during tempering) of metal carbides and their subsequent partial redissolution and refinement (during reaustenitization), in addition to the reduction in the prior austenite grain size during the cycling operation have all been suggested to contribute to the observed improvement in the mechanical properties. In this investigation, 300M steel was initially austenitized at 1143°K and then subjected to intermediate tempering at 923°K for 1 hr. before reaustenitizing at 1123°K for a short time and final tempering at 583°K. The changes in the microstructure responsible for the improvement in the properties have been studied and compared with conventionally heat treated steel. Fig. 1 shows interlath films of retained austenite produced during conventionally heat treatment.

“In vitro” and in Animal Model Studies on a Double Virus- Inactivated Factor VIII Concentrate

1995 ◽  
Vol 74 (03) ◽  
pp. 868-873 ◽  
Author(s):  
Silvana Arrighi ◽  
Roberta Rossi ◽  
Maria Giuseppina Borri ◽  
Vladimir Lesnikov ◽  
Marina Lesnikov ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Animal Model ◽  
Factor Viii ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Virus Inactivation ◽  
Enveloped Viruses ◽  
Model Studies ◽  
Heat Treated

SummaryTo improve the safety of plasma derived factor VIII (FVIII) concentrate, we introduced a final super heat treatment (100° C for 30 min) as additional virus inactivation step applied to a lyophilized, highly purified FVIII concentrate (100 IU/mg of proteins) already virus inactivated using the solvent/detergent (SID) method during the manufacturing process.The efficiency of the super heat treatment was demonstrated in inactivating two non-lipid enveloped viruses (Hepatitis A virus and Poliovirus 1). The loss of FVIII procoagulant activity during the super heat treatment was of about 15%, estimated both by clotting and chromogenic assays. No substantial changes were observed in physical, biochemical and immunological characteristics of the heat treated FVIII concentrate in comparison with those of the FVIII before heat treatment.

Vanadium Additions to a High-Cr White Iron and its Effects on the Abrasive Wear Behavior.

MRS Advances ◽  
2020 ◽  
Vol 5 (59-60) ◽  
pp. 3077-3089
Author(s):  
Alexeis Sánchez ◽  
Arnoldo Bedolla-Jacuinde ◽  
Francisco V. Guerra ◽  
I. Mejía
Keyword(s):  
Heat Treatment ◽  
Abrasive Wear ◽  
Volume Fraction ◽  
Wear Behavior ◽  
Wear Behaviour ◽  
White Iron ◽  
Heat Treated ◽  
Bulk Hardness ◽  
Abrasive Wear Behavior ◽  
Vanadium Carbides

AbstractFrom the present study, vanadium additions up to 6.4% were added to a 14%Cr-3%C white iron, and the effect on the microstructure, hardness and abrasive wear were analysed. The experimental irons were melted in an open induction furnace and cast into sand moulds to obtain bars of 18, 25, and 37 mm thickness. The alloys were characterized by optical and electronic microscopy, and X-ray diffraction. Bulk hardness was measured in the as-cast conditions and after a destabilization heat treatment at 900°C for 45 min. Abrasive wear resistance tests were undertaken for the different irons according to the ASTM G65 standard in both as-cast and heat-treated conditions under a load of 60 N for 1500 m. The results show that, vanadium additions caused a decrease in the carbon content in the alloy and that some carbon is also consumed by forming primary vanadium carbides; thus, decreasing the eutectic M7C3 carbide volume fraction (CVF) from 30% for the base iron to 20% for the iron with 6.4%V;but overall CVF content (M7C3 + VC) is constant at 30%. Wear behaviour was better for the heat-treated alloys and mainly for the 6.4%V iron. Such a behaviour is discussed in terms of the CVF, the amount of vanadium carbides, the amount of martensite/austenite in matrix and the amount of secondary carbides precipitated during the destabilization heat treatment.

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