scholarly journals Characterisation of a skin secretion with adhesive properties in the ground frog Eupsophus vertebralis (Alsodidae)

Herpetozoa ◽  
2021 ◽  
Vol 34 ◽  
pp. 169-173
Author(s):  
Elkin Y. Suárez-Villota ◽  
Eliane Trovatti ◽  
Felipe A. Contreras ◽  
José J. Nuñez
Keyword(s):  
Shear Strength ◽  
Setting Time ◽  
Skin Secretion ◽  
Adhesive Properties ◽  
Practical Applications ◽  
Lap Shear ◽  
Average Shear Strength ◽  
Average Shear ◽  
Skin Secretions ◽  
Glue Secretion

Some skin secretions with adhesive properties allow frogs to distract predators and escape; their nature is poorly studied. Here, we report the sticky skin secretion released by the Patagonian frog Eupsophus vertebralis when stressed. This secretion contained ~ 50% proteins spanning 25–250 kDa and required a fast setting time to turn into strong adhesive, which worked well on synthetic and biological materials. Lap-shear assays with Eupsophus glue secretion showed average shear strength of 3.34 MPa, comparable to cyanoacrylate (5.47 MPa). These properties suggest its biotechnological value for practical applications in industrial and medical sectors.

Vacuum Brazing Incoloy 800 Using the Copper Foil

2015 ◽  
Vol 1101 ◽  
pp. 99-103
Author(s):  
Cheng Yen Wang ◽  
Ren Kae Shiue
Keyword(s):  
Shear Strength ◽  
Copper Foil ◽  
Vacuum Furnace ◽  
Vacuum Brazing ◽  
Average Shear Strength ◽  
Average Shear ◽  
Incoloy 800 ◽  
Brazed Joints ◽  
Brazed Joint ◽  
Time Average

The purpose of this research is focused on vacuum furnace brazing Incoloy 800 (IN-800) using the copper filler foil. Microstructural evolution and shear strength of brazed joints for various brazing conditions has been evaluated in the experiment. The Cu-rich matrix dominates entire brazed joint. The width of Cu-rich matrix is decreased with increasing the brazing temperature and/or time. Average shear strength of the joint is approximately 215 MPa. Dimple dominated fracture is widely observed for the specimen brazed below 1160oC. However, cleavage dominated fracture is found for the specimen brazed at 1200oC. It is advised that copper brazing IN-800 alloy should be confined below 1160oC.

Shear strength and cracking behavior of Cr coatings on zirconium alloy fuel claddings at different strain rates

2021 ◽  
pp. 2150194
Author(s):  
Xiulin Yan ◽  
Ruiqian Zhang ◽  
Yan Liu ◽  
Yunhua Zhang ◽  
Hui Chen
Keyword(s):  
Shear Strength ◽  
Interfacial Shear Strength ◽  
Strain Rates ◽  
Cracking Behavior ◽  
Shear Lag Model ◽  
Loading Direction ◽  
Average Shear Strength ◽  
Average Shear ◽  
Lag Model ◽  
Cr Coating

Cr coating on Zr-based fuel tubes is a potential approach for the development of accident tolerant fuels (ATF). To settle the cracking behavior and quantitative evaluation of shear strength of Cr coating under different loading conditions, the average shear strength between Cr coating and zircaloy substrate has been estimated using a modified shear-lag model in this paper. Its key parameters are determined experimentally, and the tensile method has been used to research the cracking behavior of Cr coating under different strain rates. The results show that with the increase of strain rate, the interfacial shear strength increases because of the decrease of cracking spacing, while the shear strength changes erratically with the coating thickness increases. Furthermore, abundant two unequal-crack-spacings and few two equal-crack-spacings are observed which are perpendicular to the loading direction.

scholarly journals Infrared Brazing of CoCrFeMnNi Equiatomic High Entropy Alloy Using Nickel-Based Braze Alloys

Entropy ◽  
2019 ◽  
Vol 21 (3) ◽  
pp. 283 ◽  
Author(s):  
Chieh Lin ◽  
Ren-Kae Shiue ◽  
Shyi-Kaan Wu ◽  
Huai-Li Huang
Keyword(s):  
Shear Strength ◽  
Grain Boundary ◽  
High Entropy Alloy ◽  
Solidification Shrinkage ◽  
Vacuum Brazing ◽  
High Entropy ◽  
Average Shear Strength ◽  
Average Shear ◽  
Brazed Joints ◽  
Liquidus Temperatures

Infrared vacuum brazing of CoCrFeMnNi high entropy alloy (HEA) using BNi-2 and MBF601 fillers has been investigated. Both brazes show poor wettability at temperatures only 20 °C above their liquidus temperatures. However, the wettability of BNi-2 and MBF601 fillers on CoCrFeMnNi HEA is greatly improved with increasing the test temperatures, 50 °C above their liquidus temperatures. The BNi-2 brazed joints are dominated by Ni-rich matrix with huge CrB and a few tiny boride precipitates. Average shear strengths of joints increase with increasing brazing temperature and/or time, and fracture location changes from blocky CrB in the brazed zone to grain boundary boride in the substrate. The MBF601 brazed joints are composed of CoCrFeMnNi-based matrix, particles of B/Co/Cr/Fe/Mn/Ni/P compounds, and some phosphides form along the grain boundaries of the substrate. The specimen brazed with MBF601 filler foil at 1050 °C for 600 s has the highest average shear strength of 321 MPa, while that brazed at 1080 °C for 600 s has a lower average shear strength of 271 MPa due to the presence of solidification shrinkage voids.

Diffusion Barrier Effect of Carbide Layer on Bonding Characteristics of Ti/Steel Clad

1996 ◽  
Vol 458 ◽  
Author(s):  
Y. Morizono ◽  
M. Nishida ◽  
A. Chiba
Keyword(s):  
Stainless Steel ◽  
Shear Strength ◽  
Reaction Layer ◽  
Holding Time ◽  
Barrier Effect ◽  
Parent Materials ◽  
Prolonged Annealing ◽  
Average Shear Strength ◽  
Average Shear ◽  
Bonding Characteristics

ABSTRACTBonding characteristics and interfacial microstructures in explosively welded Ti/stainless steel clad of the as-welded and annealed states were investigated. In case of Ti/SUS430 ferritic stainless steel combination, the average shear strength of an as-welded clad was 555 MPa, and metastable phases such as amorphous and fine crystalline phases were observed at the interface. These were considered to be the trace of melting and subsequently rapid solidification at the contact surface of both the parent materials. By annealing below 1173 K, the strength gradually decreased with increasing holding time. The average shear strength of the clad annealed at 1073 K for 360 ks was 242 MPa, while that of the clad annealed at 1273 K abruptly decreased down to 107 MPa with increasing holding time up to 360 ks. The reaction layer formed at the interface consisted only of TiC in the former. On the other hand, the coexistence of TiC, TiFe, TiFe2 and χ was observed at the interface in the latter. The TiC in the former was considered to serve as a barrier for diffusion of Ti, Fe and Cr across the interface and to suppress the formation of intermetallic compounds. As a result, the growth of reaction layer was inhibited and high bonding strength was preserved even after prolonged annealing. The results of the Combination of Ti and SUS304 austenitic stainless steel were also discussed.

Effect of brazing temperatures on microstructure and properties of TC4/Ti57Zr13Cu21Ni9/316L

2022 ◽  
Vol 119 (1) ◽  
pp. 106
Author(s):  
Mei Yang ◽  
Shuang Li ◽  
Xianju Zhang ◽  
Honglang Yang ◽  
Liping Nie ◽  
...  
Keyword(s):  
Solid Solution ◽  
Titanium Alloy ◽  
Shear Strength ◽  
Energy Dispersive Spectrometer ◽  
Nuclear Industry ◽  
Specific Strength ◽  
Tc4 Titanium Alloy ◽  
Average Shear Strength ◽  
Average Shear ◽  
Different Temperatures

Titanium alloy is an important metal material with excellent specific strength, which is widely used in aerospace field, nuclear industry, chemical medicine, and military industry. In order to investigate the connection conditions of TC4 titanium alloy and 316L stainless steel at different temperatures, the braze welding measurement with Ti57Zr13Cu21Ni9 filler metal was conducted in vacuum. The microstructure, morphology and phase of the joint were characterized by SEM (scanning electron microscope), EDS (Energy Dispersive Spectrometer) and XRD (X-ray diffraction), respectively. Microhardness and shear strength of the joint at room temperature and the bonding mechanism of TC4 and 316L were also investigated. The obtained results revealed that the main phases in the diffusion layer were Ti-based solid solution and Ti-Fe (TiFe and TiFe2) intermetallic compoundsands (IMCs) the center of the braze was mainly composed of Ti-Fe IMCs, (Ti, Zr)2(Ni, Cu), Ti-based solid solution. Additionally, the increase of brazing temperature firstly increased and then decreased the average shear strength with the maximum value of 133.9 MPa at 960 °C.

Lead-Free Alternatives for Interconnects in High-Temperature Electronics

2017 ◽  
Author(s):  
Sandeep Mallampati ◽  
Liang Yin ◽  
David Shaddock ◽  
Harry Schoeller ◽  
Junghyun Cho
Keyword(s):  
Thermal Conductivity ◽  
Plastic Deformation ◽  
Shear Strength ◽  
High Temperature ◽  
Heat Dissipation ◽  
Volume Fraction ◽  
High Volume ◽  
Die Attach ◽  
Average Shear Strength ◽  
Average Shear

Predominant high melting point solders for high temperature and harsh environment electronics (operating temperatures from 200 to 250°C) are Pb-based systems, which are being subjected to RoHS regulations because of their toxic nature. In this study, high bismuth (Bi) alloy compositions with Bi-XSb-10Cu (X from 10 wt.% to 20 wt.%) were designed and developed to evaluate their potential as high-temperature, Pb-free replacements. Reflow processes were developed to make die-attach samples made out of the cast Bi alloys. In particular, die-attach joints made out of Bi-15Sb-10Cu alloy exhibited an average shear strength of 24 MPa, which is comparable to that of commercially available high Pb solders. These alloy compositions also retained original shear strength even after thermal shock between −55°C and +200°C and high temperature storage at 200°C. Brittle interfacial fracture sometimes occurred along the interfacial NiSb layer formed between Bi(Sb) matrix and Ni metallized surface. In addition, heat dissipation capabilities, using flash diffusivity, were measured on the die-attach assembly, compared to the corresponding bulk alloys. The thermal conductivity of all the Bi-Sb alloys was higher than that of pure Bi. By creating high volume fraction of precipitates in a die-attach joint microstructure, it was feasible to further increase thermal conductivity of this joint to 24 W/m·K, which is three times higher than that of pure Bi (8 W/m·K). Bi-15Sb-10Cu alloy has so far shown the most promising performance as a die-attach material for high temperature applications (operated over 200°C). Hence, this alloy was further studied to evaluate its potential for plastic deformation. Bi-15Sb-10Cu alloy has shown limited plastic deformation in room temperature tensile testing, in which premature fracture occurred via the cracks propagated on the (111) cleavage planes of rhombohedral crystal structure of the Bi(Sb) matrix. The same alloy has, however, shown up to 7% plastic strain under tension when tested at 175°C. The cleavage planes, which became oriented at smaller angles to the tensile stress, contributed to improved plasticity in the high temperature test.

A Study on Brazing Process and Mechanical Properties of AZ31 Magnesium Alloy

2011 ◽  
Vol 418-420 ◽  
pp. 792-795
Author(s):  
Xian Xie ◽  
Gao Feng Quan ◽  
Xiue Gu ◽  
Xing Ming Liu ◽  
Jia Le Sun
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Magnesium Alloy ◽  
Lap Joint ◽  
Resistance Furnace ◽  
Magnesium Alloy Az31 ◽  
Average Shear Strength ◽  
Average Shear ◽  
Main Factors ◽  
Better Than

The brazing process of magnesium alloy AZ31 was studied, and the mechanical properties of the weld were examined, and the main factors were analyzed through brazing furnace tests in this work. Only with the protection of self-made brazing flux, a lap joint with the average shear strength of 30MPa could be obtained in an ordinary resistance furnace without inert gas protection, which is much better than that without flux in which the shear strength is lower than 10MPa.

scholarly journals Characterizing the Soldering Alloy Type Zn–Al–Cu and Study of Ultrasonic Soldering of Al7075/Cu Combination

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 27
Author(s):  
Roman Kolenak ◽  
Igor Kostolny ◽  
Jaromir Drapala ◽  
Paulina Babincova ◽  
Martin Sahul
Keyword(s):  
Shear Strength ◽  
Aluminum Alloy ◽  
Copper Substrate ◽  
Eutectic Type ◽  
Two Phase ◽  
Copper Addition ◽  
Alloy Type ◽  
Average Shear Strength ◽  
Average Shear ◽  
Ultrasonic Soldering

The aim of the research was to characterize the soldering alloy type Zn–Al–Cu and study the fluxless ultrasonic soldering of the combination of aluminum alloy type Al7075 with copper substrate. The Zn–Al–Cu solder is of the close-to-eutectic type with two phase transformations: the eutectic transformation at 378 °C and the eutectoid transformation at 285 °C. The solder microstructure is formed of a matrix composed of the solid solutions of aluminum (Al) and zinc (Zn) in which the copper phases CuZn4 and CuAl2 are precipitated. The shear strength of the soldering alloy type Zn5Al with copper addition reaches values from 167 to 187 MPa and it depends on the copper content in the solder. The bond with aluminum alloy type Al7075 is formed due to the solubility of Al in zinc solder at the formation of solid solution Al. Contrary to this observation, the bond with the copper substrate is in this case formed due to the interaction of zinc and aluminum with the copper substrate. Two new intermetallic phases, namely Al(Cu,Zn)2 and Cu3.2Zn0.7Al4.2, were formed. The average shear strength of Al7075/Zn5Al3Cu/Cu joints attained was 134.5 MPa. For comparison, the Cu/Zn5Al3Cu/Cu joint attained an average shear strength of 136.5 MPa.

scholarly journals Shear Block Test Performance of Melunak and Mengkulang

2018 ◽  
Vol 7 (3.11) ◽  
pp. 210 ◽  
Author(s):  
Nor Jihan Abd Malek ◽  
Rohana Hassan ◽  
Azmi Ibrahim ◽  
Mohammed Hasan Alhebshi
Keyword(s):  
Shear Strength ◽  
Wood Surface ◽  
Test Performance ◽  
Bonding Performance ◽  
Average Shear Strength ◽  
Glued Laminated Timber ◽  
Strength Tests ◽  
Average Shear ◽  
Block Test ◽  
Shear Block

This paper presented results of shear block test performance of tropical glued-laminated timber (glulam) from species of melunak and mengkulang. Glulam blocks were manufactured in accordance with MS758:2001. The shear block test for glue lines and the shear strength tests of melunak and mengkulang were conducted and evaluated in accordance with BS EN 14080:2013. Melunak and mengkulang produced average shear strength values of 10.62 N/mm2 and 8.19 N/mm2, respectively. In terms of wood and glue failure percentage, the results showed that melunak and mengkulang were mainly failed due to wood surface area and not due to the glue lamination in which both melunak and mengkulang showed a good bonding performance. 

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