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Volume 35, Issue 12
Displaying 1-10 of 10 articles from this issue
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Masahiro TSUKAMOTO2007 Volume 35 Issue 12 Pages 762-763
Published: December 15, 2007
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSDownload PDF (351K) -
Yasushi MATSUDA2007 Volume 35 Issue 12 Pages 764-766
Published: December 15, 2007
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSWe have developed new welding systems using the fiber laser technology. These new systems provide better beam quality and stability compared to conventional laser welder lamp pumped Nd: YAG laser. For this development, we have developed a fiber coupled laser diode module as its pump source. Air crad structure fiber is used as active fiber. The welders also have power feedback system which can control output power accurately.View full abstractDownload PDF (8867K) -
Toshiya SHIBAYANAGI, Masahiro TSUKAMOTO, Nobuyuki ABE2007 Volume 35 Issue 12 Pages 767-771
Published: December 15, 2007
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSThe newly developed laser spot heating system is explained regarding a concept of heterogeneity in polycrystalline microstructure. The present heating system enables a collimated laser beam focus on specimen surface with a diameter less than 10μm. Effectiveness of the present spot heating method is verified as follows. The spot heating yielded a cluster composed of recrystallized grains in the deformed matrix. Size of the cluster is around 160μm and this artificial microstructure has never been reported so far. The spot heating system can lock-on any target areas to be shot, and five-spot heating was performed to show five clusters having grains with different orientations. Texture control is also expected to be realized by the present heating system. These new findings strongly suggest that the spot heating method with a heating area comparative to the size of microstructure parameters such as grains, second phase, particles and even dense dislocation walls will enables us to fabricate peculiar microstructures that we design.View full abstractDownload PDF (3249K) -
Yousuke KAWAHITO, Seiji KATAYAMA2007 Volume 35 Issue 12 Pages 772-775
Published: December 15, 2007
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSA high-power fiber laser can produce an ultra-high peak power density of MW/mm2 level corresponding to a focused electron beam owing to its high beam quality, and is promising as one of the desirable heat sources for high-speed and deep-penetration welding. A 1.5 MW/mm2-tightly-focused 10kW fiber beam could produce fully penetrated welds in 8mm-thick Type 304 stainless steel plates at the welding speeds of less than 10m/min. Moreover, the high-speed video camera observation and the X-ray transmission real-time observation of the welding phenomena show that a sound weld bead was formed owing to the formation of a long molten pool suppressing and accommodating spattering and a stable keyhole without bubbles generated from the tip. These features of the high-power fiber laser welding are expected to lead to a further increase of industrial applications of fiber lasers.View full abstractDownload PDF (9153K) -
Muneharu KUTSUNA2007 Volume 35 Issue 12 Pages 776-782
Published: December 15, 2007
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSIn this paper, an advanced laser integrated manufacturing system and its applications to industries are introduced. In addition, development of the advanced laser integrated manufacturing system using a 2kW fiber laser for welding a car panel and laser roll welding system for dissimilar metal joints such as mild steel/high strength steel to aluminum alloys, titanium to aluminum and steel to titanium is described. The advanced laser system will be a magnificent tool for the industries. And the 4th wave of modernization will be promoted more by laser technology.View full abstractDownload PDF (23745K) -
Yuzuru UEHARA2007 Volume 35 Issue 12 Pages 783-787
Published: December 15, 2007
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSUltrafast lasers are ideal for material processing that requires high precision on the micron and sub-micron order. Many researchers have intensively pursued this topic over the last ten years. High precision processes include direct-writing of features such as channels or waveguides at or below the surface of various materials, as well as surface texturing, glass welding, and nanoparticle production. Here, we present the first industrially qualified ultrafast lasers based upon optical fiber technology that produce light pulses in the femtosecond to picosecond range with micro Joule pulse energy levels at repetition rates higher than 100 kHz. We also present new applications realized with the laser's unique performance. The performance and reliability of these laser systems opens new possibilities in commercial laser processes. This technology base, coupled with highquality engineering, provides a laser tool that can meet the demands of new, high-precision, industrial applications today.View full abstractDownload PDF (3609K) -
Toshikazu KAMIYA2007 Volume 35 Issue 12 Pages 788-792
Published: December 15, 2007
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSIt is almost a decade since SUNX Ltd. started distributing the Fiber Laser Marker to FA market. In this discourse, we introduce our effort, history, and actual cases of developing and distributing fiber laser marker based on the actual performance of handling thousands of fiber lasers. Besides, we describe the outlook for the following competitive aspects of the pulse fiber laser: short-wavelength, short-pulse, and high-power, for meeting the needs of the market.View full abstractDownload PDF (2796K) -
Minoru YOSHIDA, Hisashi SAWADA2007 Volume 35 Issue 12 Pages 793-798
Published: December 15, 2007
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSIn this paper, we report on fiber lasers of transversal-single-mode pulses that have a peak power of 10kW and pulse width of 1.5ns, operating in the 1550nm band. The laser consists of dual stage Er doped fiber amplifiers that uses a newly developed Er doped fiber (EDF) designed for high power pulse amplification. Small normalized frequency of the pulse wavelength of less than 1 enables the EDF to have a large mode field diameter for reducing non-linearity and high transmission loss over 1600 nm for reducing stimulated Raman scattering. Output pulse beams focused on a spot diameter of 11 and 4pm is capable of optical intensity of 10 and 80GW/cm2 respectively.View full abstractDownload PDF (1191K) -
Yoshihiro YAMASHITA2007 Volume 35 Issue 12 Pages 799-805
Published: December 15, 2007
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSIn the manufacturing of automotive components, press fitting technology is often used and recognized as a time- and cost-effective method. Negative tolerance in press fitted bores induces tensile stress on the bore and often causes hot cracks in weld metal. Newly developed laser press fitting technology decreases out-gassing pit in weld metal by making an optimum gas-vent hole, and prevents hot cracking with keyhole welding. The outer tube is welded by laser keyhole having a gas-vent hole made by laser forming. The manufacturing process was experimentally demonstrated and simulated by inelastic analysis.View full abstractDownload PDF (19664K) -
Ryo YASUHARA, Shigeki TOKITA, Junji KAWANAKA, Toshiyuki KAWASHIMA, Hir ...2007 Volume 35 Issue 12 Pages 806-810
Published: December 15, 2007
Released on J-STAGE: March 26, 2014
JOURNAL FREE ACCESSAs the first demonstration of Faraday effect with a TGG ceramics, the Verdet constant at room temperature was experimentally measured to be 36.4rad/Tm at 1053nm, which is same as that of a single crystal. The Verdet constant at 4.2 K was increased to 87 times greater than that at room temperature. In addition the measured thermal conductivity was in good agreement with that of the single crystal between 100 K and room temperature.View full abstractDownload PDF (987K)
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