Development of Laser Welding Methods for Cold-Rolled Thin Foils of Ni<SUB>3</SUB>Al Alloys

Aluminum alloys are extensively used in the automotive industry in response to increasing requirements for weight reduction in car body architecture. Laser welding of Al alloys has many advantages such as low heat input, narrow heat affected zone, minimal thermal distortion and flexibility. Recently, the development of high brightness lasers - thin disk lasers and fiber lasers enable long focal distance welding so that laser remote welding with scanning mirrors can be used in laser welding of Al alloys. In this study, laser remote welding was implemented to a heat shield part of an automobile by utilizing a 4kW disk laser and a 2-axis scanner. By replacing conventional resistance spot welding, the weld flange length could be reduced from 15mm to 8mm and a cycle time for each welding point could also be reduced from 3.5s to 0.6s.

Download Full-text

Ultrasonic vibration aided laser welding of Al alloys: improvement of laser welding‐quality

Journal of Laser Applications ◽

10.2351/1.4745370 ◽

1995 ◽

Vol 7 (1) ◽

pp. 38-46 ◽

Cited By ~ 27

Author(s):

J. S. Kim ◽

T. Watanabe ◽

Y. Yoshida

Keyword(s):

Laser Welding ◽

Ultrasonic Vibration ◽

Al Alloys ◽

Welding Quality

Download Full-text

Investigations of HAVAR® Alloy Using Positrons

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.331.95 ◽

2012 ◽

Vol 331 ◽

pp. 95-112 ◽

Cited By ~ 2

Author(s):

S. May Tal Beck ◽

Wolfgang Anwand ◽

Andreas Wagner ◽

Gerhard Brauer ◽

A. Beck ◽

...

Keyword(s):

Lattice Structure ◽

Positron Beam ◽

Positron Annihilation Spectroscopy ◽

Total Charge ◽

Slow Positron ◽

Positron Spectroscopy ◽

Thin Foils ◽

Transmission Electron ◽

Cold Rolled ◽

Proton Dose

A study of irradiation-induced damage in HAVAR® foils was initiated in order to extract the highest proton dose the foils can sustain. The lattice structure of HAVAR® foils in different metallurgic conditions is presented, as well as visible internal structure, measured by Transmission Electron Microscopy (TEM). Positron Annihilation Spectroscopy (PAS) techniques were used to investigate these foils, and another foil that had been irradiated to the maximal proton dose limit, set by the manufacturer to a total charge of 1 mAh (= 3.6 C). PAS techniques included Doppler broadening (DB) measurement in the SPONSOR beam and lifetime (LT) measurements, both carried at Helmholtz-Zentrum Dresden-Rossendorf (HZDR). Both positron spectroscopy methods show clear differences between the investigated foils, with distinguished characteristics for annealed, cold-rolled and irradiated foils. The advantages of using a slow positron beam to study thin foils and defect profiles, over a table-top LT spectrometer, are discussed and demonstrated by the HAVAR® measurements.

Download Full-text

The influence of pre-heat treatment on laser welding of T-joints of workpieces made of selective laser melting steel and cold rolled stainless steel

Optics & Laser Technology ◽

10.1016/j.optlastec.2018.05.031 ◽

2018 ◽

Vol 107 ◽

pp. 59-66 ◽

Cited By ~ 4

Author(s):

S.V. Kuryntsev

Keyword(s):

Heat Treatment ◽

Stainless Steel ◽

Laser Welding ◽

Selective Laser Melting ◽

Laser Melting ◽

T Joints ◽

Cold Rolled

Download Full-text

Measurement and Comparison of Relative Interfacial Energy Ratios in Ni and A Ni-Cr Alloy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100069168 ◽

1970 ◽

Vol 28 ◽

pp. 434-435

Author(s):

W.N. Lin ◽

L.E. Murr

Keyword(s):

Thin Films ◽

Free Energy ◽

Grain Boundary ◽

Interfacial Energy ◽

Chromium Alloy ◽

Nickel Chromium ◽

Thin Foils ◽

Energy Ratios ◽

Cold Rolled ◽

Diffraction Microscopy

Initially cold-rolled and annealed (15 min. at 1060°C) sheet specimens of 0.004 in. thick nickel (99. 86%) and 0.005 in. thick nickel-chromium alloy (78% Ni, 20% Cr, 0.3%Mn, 1.7% Si) were electropolished to a thickness of 1000-3000 Å in a solution containing 240cm3 H2O, 340 cm3 H2SO4 and 420 cm3H3PO4. Coherent twin-grain boundary inter sections in these Ni and Ni-Cr alloy thin films were examined by transmission and diffraction microscopy. Figs. 1 and 2 illustrate the typical twin-grain boundary intersecting systems observed in Ni and Ni-Cr alloy thin foils respectively. The ratios of twin boundary free energy to grain boundary free energy, γtb/γgb, were measured by using the techniques outlined by Murr and Murr, et al.

Download Full-text

Three Surface TEM Observations of Cold Rolled 1100 Aluminum

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100096977 ◽

1981 ◽

Vol 39 ◽

pp. 50-51

Author(s):

D. L. Rohr ◽

S. S. Hecker

Keyword(s):

Room Temperature ◽

Rolling Direction ◽

Plastic Strains ◽

Thickness Direction ◽

Sheet Surface ◽

Thin Foils ◽

Cold Rolled ◽

Rolled Plates

As part of an on-going study of 1100 Al at large plastic strains, we have examined cold-rolled samples from three orientations; through the sheet surface, and in the thickness direction along the rolling direction (RD) and transverse to the RD. Cell and subgrain sizes were determined in the same manner as for the earlier work.The starting plates of 1100 Al were annealed at 500 C and then rolled at room temperature to various thicknesses. These rolled plates were used to produce final samples rolled to 0.5 mm thickness with 62, 80, and 90% reductions. Thin foils were produced by lapping and jet electropolishing. A method was developed to make thin foils perpendicular to the sheet by lapping small pieces of sheet (1 mm wide) edgewise from both edges. This produces sheet 0.25 mm thick by 0.5 mm wide which were mounted between two 0.25-mm-thick 1100 Al disks 3 mm in dia. These disks had been slitted in the center to have slits ≪ 0.5 mm wide.

Download Full-text

On the disappearance of fine, disc-like features from thin foils of steel

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100087355 ◽

1991 ◽

Vol 49 ◽

pp. 608-609

Author(s):

S. W. Thompson

Keyword(s):

Room Temperature ◽

Sheet Steel ◽

Rolled Sheet ◽

Steel Company ◽

Thin Foils ◽

Transmission Electron ◽

Fine Carbide ◽

Iced Water ◽

Cold Rolled ◽

Carbide Particles

Fine carbide particles form in quenched-and-aged specimens of iron containing a small amount of carbon. Similar precipitation occurs in ferrite grains within dual-phase steels. The particles have been described as discs or loops, typically about 20 run in diameter and 2 nm thick, which lie on ﹛100﹜ planes within ferrite grains. The precipitates are believed to form in association with vacancies and produce increases in hardness and yield strength. Two studies showed that these features disappeared after heating specimens in the transmission electron microscope (TEM), and this note reports further on this phenomenon.Continuously annealed and cold-rolled sheet steel (provided by Inland Steel Company) contained (in wt pet) 0.087 C, 0.97 Mn, 0.27 Si, 0.034 Al, 0.008 S, and 0.005 N. Specimens were intercritically annealed at 770°C for five minutes and quenched in iced water. Tensile testing was conducted within one day of heat treatment, and then specimens were stored at room temperature for about six months. Thin foils were produced by conventional thinning methods and jet polished at 75 V and 80 mA in an electrolyte containing 95% acetic acid and 5% perchloric acid. Specimens were examined in a Philips EM400 operated at 120 kV.

Download Full-text