scholarly journals Preparation and Properties of Electrospun Phenylethynyl—Terminated Polyimide Nano-Fibrous Membranes with Potential Applications as Solvent-Free and High-Temperature Resistant Adhesives for Harsh Environments

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1525
Author(s):  
Hao-ran Qi ◽  
Deng-xiong Shen ◽  
Yan-jiang Jia ◽  
Yuan-cheng An ◽  
Hao Wu ◽  
...  
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Elevated Temperatures ◽  
Solvent Free ◽  
High Tech ◽  
Molecular Weights ◽  
Lap Shear ◽  
High Adhesion ◽  
Potential Applications ◽  
Fibrous Membranes

High-temperature-resistant polymeric adhesives with high servicing temperatures and high adhesion strengths are highly desired in aerospace, aviation, microelectronic and other high-tech areas. The currently used high-temperature resistant polymeric adhesives, such as polyamic acid (PAA), are usually made from the high contents of solvents in the composition, which might cause adhesion failure due to the undesirable voids caused by the evaporation of the solvents. In the current work, electrospun preimidized polyimide (PI) nano-fibrous membranes (NFMs) were proposed to be used as solvent-free or solvent-less adhesives for stainless steel adhesion. In order to enhance the adhesion reliability of the PI NFMs, thermally crosslinkable phenylethynyl end-cappers were incorporated into the PIs derived from 3,3’,4,4’-oxydiphthalic anhydride (ODPA) and 3,3-bis[4-(4-aminophenoxy)phenyl]phthalide (BAPPT). The derived phenylethynyl-terminated PETI-10K and PETI-20K with the controlled molecular weights of 10,000 g mol−1 and 20,000 g mol−1, respectively, showed good solubility in polar aprotic solvents, such as N-methyl-2-pyrrolidinone (NMP) and N,N-dimethylacetamide (DMAc). The PI NFMs were successfully fabricated by electrospinning with the PETI/DMAc solutions. The ultrafine PETI NFMs showed the average fiber diameters (dav) of 627 nm for PETI-10K 695 nm for PETI-20K, respectively. The PETI NFMs showed good thermal resistance, which is reflected in the glass transition temperatures (Tgs) above 270 °C. The PETI NFMs exhibited excellent thermoplasticity at elevated temperatures. The stainless steel adherends were successfully adhered using the PETI NFMs as the adhesives. The PI NFMs provided good adhesion to the stainless steels with the single lap shear strengths (LSS) higher than 20.0 MPa either at room temperature (25 °C) or at an elevated temperature (200 °C).

ACI TYPE CF-12M

Alloy Digest ◽  
1965 ◽  
Vol 14 (4) ◽  
Keyword(s):  
Fracture Toughness ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Alloy Steel ◽  
Elevated Temperatures ◽  
Heat Treating ◽  
Temperature Performance

Abstract Type CF-12M is a chromium-nickel-molybdenum alloy steel having corrosion resistance and good strength at moderately elevated temperatures. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness and creep. It also includes information on low and high temperature performance, and corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: SS-167. Producer or source: Stainless steel foundries.

Evaluation of High Temperature Properties and Microstructural Characterization of Resistance Spot Welded Steel Lap Shear Joints

2016 ◽  
Vol 35 (2) ◽  
pp. 145-151
Author(s):  
R. K. Gupta ◽  
V. Anil Kumar ◽  
Paul G. Panicker
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Joint Strength ◽  
Microstructural Characterization ◽  
Parent Metal ◽  
Resistance Spot ◽  
Lap Shear ◽  
Stainless Steel 304 ◽  
Ss 304 ◽  
Spot Welded

AbstractJoining of thin sheets (0.5 mm) of stainless steel 304 and 17-4PH through resistance spot welding is highly challenging especially when joint is used for high temperature applications. Various combinations of stainless steel sheets of thickness 0.5 mm are spot welded and tested at room temperature as well as at high temperatures (800 K, 1,000 K, 1,200 K). Parent metal as well as spot welded joints are tested and characterized. It is observed that joint strength of 17-4PH steel is highest and then dissimilar steel joint of 17-4PH with SS-304 is moderate and of SS-304 is lowest at all the temperatures. Joint strength of 17-4PH steel is found to be >80% of parent metal properties up to 1,000 K then drastic reduction in strength is noted at 1,200 K. Gradual reduction in strength of SS-304 joint with increase in temperature from 800 to 1,200 K is noted. At 1,200 K, joint strength of all combinations of joints is found to be nearly same. Microstructural evaluation of weld nugget after testing at different temperatures shows presence of tempered martensite in 17-4PH containing welds and homogenized structure in stainless steel 304 weld.

High-Temperature Properties of Langasite

1999 ◽  
Vol 604 ◽  
Author(s):  
H. Fritze ◽  
H. L. Tuller ◽  
G. Borchardt ◽  
T. Fukuda
Keyword(s):  
High Temperature ◽  
Oxygen Diffusion ◽  
Elevated Temperatures ◽  
Low Oxygen ◽  
Bulk Resistivity ◽  
Load Response ◽  
Oxidation Reduction ◽  
Mass Load ◽  
Potential Applications ◽  
Related Compounds

AbstractMaterials such as langasite (La3Ga5SiO14) and related compounds are promising candidates for piezoelectric applications at high temperatures. In particular, langasite does not exhibit phase transformations up to the melting point of 1470 °C. Langasite was investigated with respect to potential applications in high temperature resonator devices. In contrast to current resonator materials, we have observed bulk oscillations at temperatures of up to 750 °C in langasite devices. At 700 °C the mass load response for 0.78 mm thick resonators is approximately 0.10 µg/Hz.At elevated temperatures, the bulk resistivity of the resonator devices cannot be neglected due to attenuation of the resonance signal. Therefore, the temperature dependence of the electrical properties of langasite resonator devices, including bulk resistivity, capacity and resonance frequency were measured and are presented. The electrical conductivity is characterized by an activation energy of 105 kJ/mol. In order to confirm langasites stability with respect to oxidation-reduction reactions, we examined the oxygen diffusivity by measuring 18O tracer profiles by SIMS. The diffusivity along the Y-axis is given by D = 5-10−5 exp(-140 kJ/mol / RT) cm2/s in the temperature range from 500 to 800 °C. Langasite shows low oxygen diffusion coefficients with respect to other materials which might be investigated using a langasite microbalance. This would, for example, enable oxygen diffusion kinetics to be examined in YBa2Cu3O6 at 600 °C by means of 18O/16O exchange.

High Temperature Deformation and Diffusion Brazing of INCONEL 718 Sheet

2014 ◽  
Vol 622-623 ◽  
pp. 508-513
Author(s):  
Yong Nam Kwon ◽  
S.S. Hong ◽  
H.G. Kim
Keyword(s):  
High Temperature ◽  
Diffusion Bonding ◽  
Inconel 718 ◽  
Elevated Temperatures ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Manufacturing Cost ◽  
Lap Shear ◽  
Diffusion Brazing ◽  
And Diffusion

Superplastic forming has been known for the ideal process for manufacturing complex parts. Also, diffusion bonding can give a higher design flexibility, which allows a better performance with a lower overall manufacturing cost. Fine grained INCONEL 718 alloy sheet has been known to show superplastic behavior with the combination of high strength and corrosion resistance at the elevated temperatures. In the present study, high temperature deformation characteristic of INCONEL 718 sheet with 15m was investigated firstly. Then, blow forming process with cylindrical cavity was tried. Also, best diffusion brazing and bonding condition was tried to be defined in terms of temperature, pressure and time. Bonding strength was characterized by using lap shear type test and interface observation. Characteristics of deformation and diffusion bonding at high temperature were influenced greatly with grain size while Nb precipitate also played an important role.

scholarly journals Evaluation of raw and chemically treated waste phosphogypsum and its potential applications

2019 ◽  
Vol 96 ◽  
pp. 02004
Author(s):  
Tebogo Mashifana
Keyword(s):  
High Temperature ◽  
Citric Acid ◽  
Construction Industry ◽  
South African ◽  
Elevated Temperatures ◽  
Relative Proportion ◽  
Cement Industry ◽  
Limited Ability ◽  
Moisture Contents ◽  
Potential Applications

A million tons of Phosphogypsum (PG) is stacked in the environment every year and is progressively considered an asset. South African construction industry is expanding as a result of infrastructural developments in the country, the reuse of PG in this industry is considered for recycling and reducing the stacks in landfills. Phosphogypsum is known for its limited ability to use in cement industry due to its phosphorus and radionuclides impurities. This study was conducted to reduce these impurities and investigate the probability of PG application in building and construction. Leaching of PG with citric acid was conducted whereby a relative proportion of P2O5 and radionuclides was reduced in the material, constituents which contributes to strengths reduction. Optimum moisture Contents and maximum dry densities were determined for various PG content mix designs in which Lime and Fly Ash were added to stabilise PG material. The composites were compacted at various moisture contents and cured at low and elevated temperatures of at 40 °C and 80 °C for 4 days. The results obtained shows that for unconfined compressive strengths; the composites produced from PG, and cured at high temperature qualified for the use in construction industry.

scholarly journals Properties and structure of high temperature resistant cyanate ester/polyethersulfone blends using solvent-free toughening approach

2020 ◽  
Author(s):  
Lyaysan Amirova ◽  
Fabian Schadt ◽  
Markus Grob ◽  
Christian Brauner ◽  
Thomas Ricard ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Temperature ◽  
Network Formation ◽  
Mechanical Analysis ◽  
Solvent Free ◽  
Cyanate Ester ◽  
Low Molecular Weight ◽  
Scanning Calorimetry ◽  
Molecular Weights ◽  
The Difference

AbstractA high temperature resistant novolac cyanate ester was blended with polyethersulfone (PES) with different molecular weights using the solvent-free approach. The phase separation, curing behavior and thermal properties were studied using hot stage microscopy, differential scanning calorimetry and dynamic mechanical analysis. Results showed the difference in the morphology for blends with different molecular weight PES explained by possible network formation. The influence of PES content on the glass transition temperature and mechanical properties was investigated. The most significant toughening effect (increase of 132% in fracture toughness) was achieved on a functionalized low molecular weight PES (20 parts per hundred of resin, phr). Rheology investigation allowed to estimate the optimal content of PES (15 phr) for further prepreg manufacturing.

CROLOY 16-13-3

Alloy Digest ◽  
1967 ◽  
Vol 16 (11) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Stainless Steels ◽  
Elevated Temperatures ◽  
Heat Treating ◽  
Oil Refinery ◽  
Paper Pulp ◽  
Temperature Performance ◽  
Pulp Processing

Abstract Croloy 16-13-3 is a molybdenum-containing 18-12 type austenitic stainless steel having better corrosion resistance than the 18-8 type stainless steels. It is recommended for corrosion resisting applications in the chemical and oil refinery industries, paper pulp processing, etc. In addition to corrosion resistance, this alloy is characterized by superior resistance to creep at elevated temperatures. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: SS-202. Producer or source: Babcock & Wilcox Company.

CRUTEMP 25

Alloy Digest ◽  
1975 ◽  
Vol 24 (4) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Control Systems ◽  
Gas Turbines ◽  
Elevated Temperatures ◽  
High Strength ◽  
Heat Treating ◽  
Temperature Performance ◽  
Automotive Emission

Abstract CRUTEMP 25 is a fully austenitic stainless steel with outstanding resistance to scaling at elevated temperatures. It also has high strength at elevated temperatures and its weldability is excellent. It is used in such applications as automotive emission control systems and gas turbines. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-309. Producer or source: Crucible Stainless Steel Division, Colt Industries.

ACI TYPE HF

Alloy Digest ◽  
1963 ◽  
Vol 12 (5) ◽  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
High Temperature ◽  
High Resistance ◽  
Elevated Temperatures ◽  
High Strength ◽  
Heat Treating ◽  
Temperature Performance ◽  
Resistance To Oxidation ◽  
Iron Chromium

Abstract Type HF is an austenitic iron-chromium-nickel alloy offering high resistance to oxidation at elevated temperatures, high strength and corrosion resistance. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance and corrosion resistance as well as casting, heat treating, machining, and joining. Filing Code: SS-143. Producer or source: Stainless steel foundries.

ARMCO PH 15-7Mo STAINLESS STEEL

Alloy Digest ◽  
1997 ◽  
Vol 46 (8) ◽  
Keyword(s):  
Heat Treatment ◽  
Stainless Steel ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Elevated Temperatures ◽  
High Strength ◽  
Heat Treating ◽  
Good Corrosion Resistance ◽  
Temperature Performance ◽  
Minimal Distortion

Abstract Armco PH 15-7 Mo stainless steel is a Cr-Ni-Mo-Al semi-austenitic stainless steel. It is heat treatable to high strength and hardness, maintains good corrosion resistance, and undergoes minimal distortion from heat treatment. The alloy has applications in the aerospace and other industries where high strength at elevated temperatures is required. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, and joining. Filing Code: SS-693. Producer or source: Armco Inc., Specialty Steels Division.

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