scholarly journals Influence of parameters of impulse laser impact on the formation of the gradient of the structure of porous titanium powder

2018 ◽  
pp. 88-94
Author(s):  
D. V. Minko
Keyword(s):  
Laser Radiation ◽  
Titanium Powder ◽  
Structural Characteristics ◽  
Selective Laser Sintering ◽  
Light Flux ◽  
Laser Action ◽  
Pulsed Laser ◽  
Powder Materials ◽  
Solid Core ◽  
Powder Particles

The possibility of selective laser sintering of graded porous and compactly porous structures by surface fusion of powder particles is demonstrated while maintaining a solid core, which leads to the formation of interparticle contacts in the presence of a liquid phase. The interaction of the light flux of the laser pulse with the surface of the powder particles under multiple reflection is considered. It is shown that the effect of single pulses of laser radiation leads to the formation of sintered structural elements of a powder material having a diameter approximately equal to the diameter of the focal spot. Technological regimes of pulsed laser action are established at which steady contact formation of titanium powder particles of the fractional compositions under study occurs. The possibility of obtaining powder materials with a gradient structure by controlling the parameters of pulsed laser action is experimentally demonstrated. It was found that accurate dosing of thermal energy and the number of pulses of laser radiation makes it possible to minimize shrinkage of powder layers in the absence of particle conglomeration, to control the structural characteristics and properties of products, to preserve the microstructure and phase composition of the initial materials.

Particularly Selective Sintering of Metal Powders by Pulsed Laser Radiation

2016 ◽  
Vol 685 ◽  
pp. 403-407 ◽  
Author(s):  
V.G. Smelov ◽  
A.V. Sotov ◽  
Serguei P. Murzin
Keyword(s):  
Laser Radiation ◽  
Metal Powder ◽  
Development Process ◽  
Selective Laser Sintering ◽  
Pulsed Laser ◽  
Laser Sintering ◽  
Material Structure ◽  
Metal Powders ◽  
Pulsed Laser Radiation ◽  
Fine Powders

In this article, selective laser sintering of fine metal powder of pure Ni with the size fractions 56 ... 80 microns was conducted. Algorithm development process of laser sintering of fine powders was created, allowing to obtain defect-free samples. Investigation of the material structure of obtained samples was carried out.

Active Interlayer Heating for Sustainable Selective Laser Sintering With Reclaimed Polyamide 12 Powders

2020 ◽  
Author(s):  
Feifei Yang ◽  
Tianyu Jiang ◽  
Xu Chen ◽  
Greg Lalier ◽  
John Bartolone
Keyword(s):  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Economic Losses ◽  
Powder Materials ◽  
Elongation At Break ◽  
Polyamide 12 ◽  
Process Failure ◽  
Powder Particles ◽  
Recycle And Reuse ◽  
Sintering Processes

Abstract Selective laser sintering (SLS) technology produces a substantial amount of un-sintered polyamide 12 powders after the manufacturing process. Failure to recycle and reuse these aged powders not only leads to economic losses but also is environmentally unfriendly. This is particularly problematic for powder particles close to the heat-affected zones that go through severe thermal degradations during the laser sintering processes. Limited procedures exist for systematically reusing such extremely aged powders. This work proposes a systematic method to maximize reusability of aged and extremely aged polyamide 12 powders. Building on a previously untapped interlayer heating, pre-processing, and a systematic mixing of powder materials, we show how reclaimed polyamide 12 powders can be consistently reprinted into functional samples, with mechanical properties even superior to current industrial norms. In particular, the proposed method can yield printed samples with 18.04% higher tensile strength and 55.29% larger elongation at break using as much as 30% of extremely aged powders compared to the benchmark sample.

Influence of Continuous and Pulsed Laser Radiation on Optical and Thermal Properties of Biological Tissues

2014 ◽  
Vol 59 (12) ◽  
pp. 1149-1154
Author(s):  
A.D. Mamuta ◽  
◽  
V.S. Voitsekhovich ◽  
N.M. Kachalova ◽  
L.F. Golovko ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Laser Radiation ◽  
Pulsed Laser ◽  
Biological Tissues ◽  
Pulsed Laser Radiation

scholarly journals Effects of pulsed laser radiation on epitaxial self-assembled Ge quantum dots grown on Si substrates

2011 ◽  
Vol 22 (29) ◽  
pp. 295304 ◽  
Author(s):  
A Pérez del Pino ◽  
E György ◽  
I C Marcus ◽  
J Roqueta ◽  
M I Alonso
Keyword(s):  
Quantum Dots ◽  
Laser Radiation ◽  
Pulsed Laser ◽  
Pulsed Laser Radiation ◽  
Si Substrates ◽  
Ge Quantum Dots ◽  
Self Assembled

Treatment of ultrafine aluminum alloys with pulsed laser radiation

2007 ◽  
Vol 36 (5) ◽  
pp. 467-470 ◽  
Author(s):  
P. Yu. Kikin ◽  
V. N. Perevezentsev ◽  
A. I. Pchelintsev ◽  
E. E. Rusin
Keyword(s):  
Laser Radiation ◽  
Aluminum Alloys ◽  
Pulsed Laser ◽  
Pulsed Laser Radiation ◽  
Ultrafine Aluminum

Annealing of Defects in Ion-Implanted Layers by Pulsed Laser Radiation

1977 ◽  
pp. 445-451 ◽  
Author(s):  
G. A. Kachurin ◽  
V. A. Bogatyriov ◽  
S. I. Romanov ◽  
L. S. Smirnov
Keyword(s):  
Laser Radiation ◽  
Pulsed Laser ◽  
Pulsed Laser Radiation ◽  
Ion Implanted

scholarly journals Temperature Calibration Measurements based on Laser-Induced Phosphorescence Technique for Combustion Applications

2015 ◽  
Vol 10 (1) ◽  
Keyword(s):  
Laser Radiation ◽  
Laser Beam ◽  
Intensity Ratio ◽  
Laser Power ◽  
Room Temperature ◽  
Pulsed Laser ◽  
Temperature Calibration ◽  
Phosphor Powder ◽  
Calibration Methods

Phosphor powder and phosphor-binder mixtures are successfully employed for temperature calibration measurements by using laser-induced phosphorescence (LIP) technique with an emphasis on higher precisions and accuracies than other non-intrusive methods. The phosphorescence intensities are used to perform these calibrations in three different strategies. The influence of laser power regular changes on particles heating and the calibration analyses is also carried out. A pulsed laser at 355 nm was used for exciting specimens of the phosphor powder as well as the phosphor-binder mixtures. The laser beam was directed onto the specimens and varied in three laser power levels (LPLs). The samples were kept in an oven with temperatures ranging from room temperature up to 1800 °C. The three strategies which are expressed in terms of non-dimensional intensity versus wavelength (NDI-W), normalised intensity (NI) and intensity ratio (IR) were used for the calibration assessments. A modified IR was compared with two different IRs. A precision of around ± (0.50-1.41)% was attained for different calibration methods. This research confirmed that these calibrations are possible using three different strategies, given high precisions and accuracies. The laser power alternations influenced the NI and do affect neither the NDI-W nor the IR curves. The laser radiation does not play any role for heating the particles of the studied powder.

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