scholarly journals Methods for Estimating the Parameters of Average Shear Strength alnog the Slip Surface

Landslides ◽  
1984 ◽  
Vol 20 (4) ◽  
pp. 1-6_1 ◽  
Author(s):  
Seiichi GIBO ◽  
Aritsune TAKEI ◽  
Seiryo KOHAGURA
2015 ◽  
Vol 1101 ◽  
pp. 99-103
Author(s):  
Cheng Yen Wang ◽  
Ren Kae Shiue

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.


Author(s):  
Xiulin Yan ◽  
Ruiqian Zhang ◽  
Yan Liu ◽  
Yunhua Zhang ◽  
Hui Chen

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.


Entropy ◽  
2019 ◽  
Vol 21 (3) ◽  
pp. 283 ◽  
Author(s):  
Chieh Lin ◽  
Ren-Kae Shiue ◽  
Shyi-Kaan Wu ◽  
Huai-Li Huang

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.


1996 ◽  
Vol 458 ◽  
Author(s):  
Y. Morizono ◽  
M. Nishida ◽  
A. Chiba

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.


Herpetozoa ◽  
2021 ◽  
Vol 34 ◽  
pp. 169-173
Author(s):  
Elkin Y. Suárez-Villota ◽  
Eliane Trovatti ◽  
Felipe A. Contreras ◽  
José J. Nuñez

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.


2022 ◽  
Vol 119 (1) ◽  
pp. 106
Author(s):  
Mei Yang ◽  
Shuang Li ◽  
Xianju Zhang ◽  
Honglang Yang ◽  
Liping Nie ◽  
...  

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.


Author(s):  
Sandeep Mallampati ◽  
Liang Yin ◽  
David Shaddock ◽  
Harry Schoeller ◽  
Junghyun Cho

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.


2011 ◽  
Vol 418-420 ◽  
pp. 792-795
Author(s):  
Xian Xie ◽  
Gao Feng Quan ◽  
Xiue Gu ◽  
Xing Ming Liu ◽  
Jia Le Sun

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.


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