scholarly journals Ultrasonic Bonding of Multi-Layered Foil Using a Cylindrical Surface Tool

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 505
Author(s):  
Arimoto ◽  
Sasaki ◽  
Doi ◽  
Kim
Keyword(s):  
Relative Motion ◽  
Cylindrical Surface ◽  
High Speed ◽  
Image Correlation ◽  
In Situ Observation ◽  
Copper Sheet ◽  
Bonding Material ◽  
Ultrasonic Bonding ◽  
Tool Surface

A cylindrical tool was applied for ultrasonic bonding of multi-layered copper foil and a copper sheet to prevent damage to the foil during bonding. The strength of the joints bonded with the cylindrical tool was comparable to that of the joints bonded with a conventional knurled tool. The effect of the cylindrical surface tool on bondability was investigated thorough relative motion behaviors between the tool surface and the bonding materials, as well as on bond microstructure evolution. The relative motion was visualized with in-situ observation using a high-speed camera and digital image correlation. At shorter bonding times, relative motions occurred at the bonding interfaces of the foil and the copper sheet. Thereafter, the relative motion between the tool and the bonding material became predominant owing to bond formation at the bonding interface, resulting in a macroscopic plastic flow in the bonded region. This relative motion damaged the foil in knurled tool bonding, and the cylindrical tool achieved bonding without any damage.

In Situ Observation Method for Quantitative Evaluation of Solidification Phenomena and Solidification Cracks during Welding

2014 ◽  
Vol 782 ◽  
pp. 3-7
Author(s):  
Kenji Shinozaki ◽  
Motomichi Yamamoto ◽  
Kohta Kadoi ◽  
Peng Wen
Keyword(s):  
High Speed ◽  
Video Camera ◽  
Solidification Cracking ◽  
In Situ Observation ◽  
High Speed Video Camera ◽  
Varestraint Test ◽  
Solidification Cracks ◽  
Observation Method ◽  
Solidification Crack

Solidification cracking during welding is very serious problem for practical use. Therefore, there are so many reports concerning solidification cracking. Normally, solidification cracking susceptibility of material is quantitatively evaluated using Trans-Varestraint test. On the other hand, local solidification cracking strain was tried to measure precisely using in-situ observation method, called MISO method about 30 years ago. Recently, digital high-speed video camera develops very fast and its image quality is very high. Therefore, we have started to observe solidification crack using in site observation method. In this paper, the local critical strain of a solidification crack was measured and the high temperature ductility curves of weld metals having different dilution ratios and different grain sizes to evaluate quantitatively the effects of dilution ratio and grain size on solidification cracking susceptibility by using an improved in situ observation method.

scholarly journals In Situ Rubber-Wheel Contact on Road Surface Using Ultraviolet-Induced Fluorescence Method

2020 ◽  
Vol 10 (24) ◽  
pp. 8804
Author(s):  
Jhonni Rahman ◽  
Yutaka Shoukaku ◽  
Tomoaki Iwai
Keyword(s):  
Contact Area ◽  
High Speed ◽  
High Sensitivity ◽  
Dynamic Contact ◽  
Road Surface ◽  
Oxide Semiconductor ◽  
Small Scale ◽  
In Situ Observation ◽  
On The Road

This study examines the relationship between rubber-wheel and the contact area on the road surface. Ultraviolet-induced fluorescence microscopy was used to observe and measure the contact parts with pyranine as a dye solution. The high sensitivity to U.V. light makes it easy to distinguish contact and non-contact regions on a very small scale. The experiment was conducted in static and dynamic conditions to identify its influence on the apparent contact area of rubber-wheel and road surface. The in-situ observation of the contact area was captured and recorded using a high-speed digital camera with 1-inch a CMOS (complementary metal oxide semiconductor) sensor. Additionally, the contact area between rubber-wheel and road surface was measured using an analyzing software. The results show differences in static and dynamic contact conditions based on the operating parameters.

Effects of Water Jet Peening and Hardening Treatment on Fatigue Properties of SCr420

2009 ◽  
Author(s):  
Akira Shimamoto ◽  
Ryo Kubota ◽  
Sung-mo Yang ◽  
Dae-kue Choi ◽  
Weiping Jia
Keyword(s):  
Fatigue Life ◽  
High Speed ◽  
Fatigue Crack Initiation ◽  
Fatigue Tests ◽  
Water Jet ◽  
Fatigue Properties ◽  
In Situ Observation ◽  
Axial Tensile ◽  
High Pressure Water Jet

An experimental study of high pressure water jet peening treatment on chromium steal SCr420 H3V2L2 is conducted to study the effects of cavitation impacts of high-speed water on fatigue crack initiation and propagation of notched specimens. There are six different kinds of specimens. First three kinds are treated with; only annealing, only water quenching, and only oil quenching. Other three kinds are treated with above heat treatment and water jet peening, respectively. An axial tensile fatigue tests’ condition is 260MPa maximum stress amplitude, 0 stress ratio and 10Hz frequency, while in-situ observation by SEM is employed. Although fatigue life of the specimens with annealing and water jet peening is shorter than that of only annealing, fatigue life of water and oil quenching with water jet peening specimens is obviously longer than those without water jet peening treatment. Water jet peening has increased residual stress inside the specimens on the latter case and raised their fatigue strength. In-situ observation on the crack tips approves above analysis.

scholarly journals Lubrication Analysis of Micro-Dimple Textured Die Surface by Direct Observation of Contact Interface in Sheet Metal Forming

Metals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 917 ◽  
Author(s):  
Shimizu ◽  
Kobayashi ◽  
Vorholt ◽  
Yang
Keyword(s):  
Metal Forming ◽  
High Speed ◽  
Sliding Friction ◽  
Flow Analysis ◽  
Hydrodynamic Pressure ◽  
Observation System ◽  
In Situ Observation ◽  
Two Phase ◽  
Micro Dimple

: To investigate the underlying mechanism of the effects of surface texturing on lubricated sliding friction in the metal forming operation, an in-situ observation system using transparent silica glass dies and a high speed recording camera was newly developed. To correlate the dimensional parameters of micro-dimple textured structures and tribological properties in the metal forming operation, the in-situ observation was performed during bending with the ironing process of the stainless steel sheet with a thickness of 0.1 mm. The lubrication behavior were compared between the different lubricant viscosities and the micro-dimple textures with different diameters of 10 µm, 50 µm, 100 µm fabricated by using femto-/pico-second laser processing. As a result, the textured die with dimple diameters of 10 µm and 50 µm showed the lubricant flow transferred from one to the other dimples owing to the lubricant reservoir effect, while that of 100 µm indicated the less supply of the lubricant. However, the textured die with a dimple diameter of 10 µm demonstrated higher ironing force than that of 50 µm, due to the severe adhesion of work materials inside the dimple structures. Based on these experimental findings, the dimple size dependencies on lubricant reservoirs effects and the generation of the hydrodynamic pressure were discussed by correlating with the in-situ observation results, a fluid-flow analysis and a laminar two-phase flow analysis using the finite element method.

scholarly journals In Situ and Post-Mortem Characterizations of Ultrasonic Spot Welded AZ31B and Coated Dual Phase 590 Steel Joints

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 899 ◽  
Author(s):  
Jian Chen ◽  
Yong Chae Lim ◽  
Donovan Leonard ◽  
Hui Huang ◽  
Zhili Feng ◽  
...  
Keyword(s):  
High Speed ◽  
Tensile Tests ◽  
Fatigue Tests ◽  
Image Correlation ◽  
Joint Interface ◽  
Welding Time ◽  
Cross Sectional ◽  
Welding Condition ◽  
Lap Shear

Ultrasonic spot welding using different welding conditions was applied to join dissimilar metals of galvanized DP590 steel and AZ31B magnesium sheets. In situ high-speed imaging, digital image correlation, and infrared thermography were utilized to quantitatively study the interfacial relative motion, surface indentation, and heat generation across the joint faying interface and the sheet/sonotrode interfaces under the welding condition of moderate welding power and short welding time. For welds made with high power and long welding time, lap shear tensile tests as well as fatigue tests were carried out. Different fracture modes were observed after the lap shear tensile tests and fatigue tests performed under different peak loads. Post-weld cross-sectional analysis with scanning electron microscopy coupled with energy dispersive X-Ray spectroscopy revealed the variation of morphology and chemical composition at the joint interface for welds made with different welding conditions.

In Situ Observation of Microwedge Effect on Liquid Lubrication

2004 ◽  
Vol 126 (4) ◽  
pp. 690-696 ◽  
Author(s):  
Sy-Wei Lo ◽  
Bo-Qi Zhou ◽  
Ching-Feng Fang ◽  
Yu-Sheng Lu
Keyword(s):  
Elastic Deformation ◽  
Average Velocity ◽  
Contact Region ◽  
Hydrodynamic Pressure ◽  
The Other ◽  
In Situ Observation ◽  
Sliding Velocity ◽  
Surface Separation ◽  
Tool Surface

The influence of the minute elastic deformation of tool surface, named the “microwedge,” on the asperity crushing in liquid lubrication is investigated experimentally. The microwedge plays a role so dominant that although increasing the average velocity of the lubricant can alleviate the asperity deformation; such efforts will be overwhelmed by the microwedge effect if the relative sliding velocity between tool and workpiece is also enhanced concurrently. For all roughness patterns, the asperities show multidirectional expansions of the contact region; an important feature of the microwedge effect. The microwedge effect also creates distributions of surface separation and hydrodynamic pressure neither expected nor explainable by the other models.

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