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Sabae, Japan

Nakamura H.,Charmant Inc. | Kawahito Y.,Osaka University | Nishimoto K.,Anan College of Technology | Katayama S.,Osaka University
Journal of Laser Applications

This study was undertaken to clarify the relationship among the laser-induced plume ejected from the keyhole, the melt flows in the molten pool, and the formation mechanisms of spatters ejected from the molten pool during 10kW laser welding of a pure titanium plate. High-speed video camera observation results showed that laser-induced plumes occurred at intervals of about 0.5ms, and that the maximum plume ejection velocity reached 250m/s. Three-dimensional X-ray transmission in-situ observation of the weld molten pool with tungsten carbide tracers revealed that the melt flowed mainly along the bottom of the molten pool from the keyhole tip to the rear part and then from the rear to the front near the surface of the molten pool at high speeds, while the melt in front of a keyhole flowed upward along the keyhole wall at a velocity of less than 0.6m/s and then was accelerated to 2.1m/s at the height of about 2mm above the keyhole inlet. One-way upward melt flows were continuously piled up at the tip of the elongated melt, resulting in spattering as droplets from the molten pool due to the strong ejection of laser-induced plumes. Spatters were formed from part of a molten metal elongated around the keyhole inlet, and approximately 20ms was required to form spatters. About 80% of spatters were generated from melts of the front or sides of the keyhole at the speeds of less than 50mm/s. When the welding speed increased from 50-100mm/s to 300mm/s, the ratio and the size of spatters occurring from the rear part of a keyhole increased from 20% to 80% and became smaller than 1mm. © 2015 Laser Institute of America. Source

Tada H.,Tohoku University | Tada H.,Charmant Inc. | Yamamoto T.,Utsunomiya University | Wang X.,Tohoku University | Kato H.,Tohoku University
Materials Transactions

The effect of Al content on superelastic properties of Ti 75-xNb 15Zr 10Al x (x = 0-6 at%) quaternary β Ti alloys were investigated. And the effects of baking for coating or plating on superelastic properties were also studied. The alloys containing 3 and 4 at% of Al clearly exhibited superelastic behavior after aging at 453 and 553K, which are appropriate temperatures for industrial coating and plating, respectively. Ti 72Nb 15Zr 10Al 3 alloy exhibited the largest recovery strain of 2.5% due to superelastic behavior even after industrial coating and plating. In this quaternary alloy system, strange non-monotonical change of superelastic behavior as a function of Al content was also found. © 2012 The Japan Institute of Metals. Source

Charmant Inc. | Date: 2012-05-25

medical scissors, catheters, cannulas, stents, medical knives, medical guidewires, medical tubing for drainage, transfusion and administering drugs, connectors for medical tubing for drainage, transfusion and administering drugs; needles for medical use; disposable medical sterilization pouches, curettes, surgical saws, surgical scissors, surgical implants comprising artificial materials, surgical clips, surgical knives, surgical compressors, surgical apparatus and instruments for medical use; surgical mirrors, artificial skin for surgical purposes, surgical blades, surgical hooks; ophthalmic instruments for medical purposes, namely, scissors, forceps, intraocular lens hooks, needle holders, needles, knives, lid retractors, capsule forceps, capsule scissors, spatulas, raspatories for lenticle; surgical instruments, namely, trocars, cannulas, valve closures, bipolar forceps, ultrasonic tips and cannulations, bone screws, dental implants, dental burrs, orthodontic machines and instruments, needle holders for medical use, surgical suture needles, orthopedic instruments for therapeutic use, orthopedic screws, orthopedic joint implants, minimally invasive medical devices, namely, capsule forceps, capsule scissors, forceps for removing anterior capsule, intraocular lens hooks, trocars, cannulas and knives, medical suture instruments, forceps.

Charmant Inc. | Date: 2014-06-10

Eyeglasses, eyeglass frames, eyeglass cases, sunglasses.

Charmant Inc. | Date: 2009-01-20

Eyeglasses, eyeglass frames and eyeglass cases.

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