11 research outputs found
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Fabrication of X-Graded H13 and Cu Powder Mix Using High Power Pulsed Nd:YAG Laser
The manufacturing of Functionally Graded Material (FGM) parts using Solid Free Form
manufacturing technologies has been carried out since early 1980. At present, most of the
powder manufacturing techniques are being focused on layering powder with different
powder blend compositions with Z gradients (graded in direction of layer build). Although,
there are a few researchers working on multi powder feeder and deposition system, the study
of laser fusion of the deposited powder (by a powder deposition system) is minimum or not
known to date. Consequently, the manufacturing of functionally graded structures is still
geometry limited. This work was focused on the manufacturing of X-graded (graded along the
powder bed plane) specimens with H13 tool steel and Cu mix. Five bimodal powder blends
were used with a multi-container feed hopper to spread powder layers for the selective laser
fusion of the powder. The powder was fused using a high power Nd:YAG pulsed laser using a
specific scanning strategy to reduce porosity. Specimens were produced with graded Cu
within the H13 matrix. The specimens were analysed for dimensional accuracy,
microstructure, porosity, cracks and micro hardness of the FGM.Mechanical Engineerin
An investigation of normal and slant laser cutting using CW and pulsed Co~2 laser for laminated object manufacturing techniques
High Density Selective Laser Melting of Waspaloy
In this work, high density Waspaloy® specimens were produced using specially assembled
laboratory equipment by Selective Laser Melting (SLM). SLM of Waspaloy® powder was
performed using a high power pulsed Nd:YAG laser. The laser parameters pulse energy (J), pulse
width (ms), repetition rate (Hz) and scan speed (mm/min) were varied. Process parameter
optimization was achieved using factorial analysis to investigate the relationship between specific
processing parameters and the formation of Waspaloy® specimens. The optimized processing
parameters produced Waspaloy® specimens that were 99.3 % dense. The resultant laser melted
specimen’s height, width and contact angles were measured. Specimens were also observed for
the occurrence of porosit
High density selective laser melting of Waspaloy (R)
n this work, high density Waspaloy® specimens were produced using selective laser melting (SLM). SLM of Waspaloy® powder was performed using a high power pulsed Nd:YAG laser. The laser parameters pulse energy (J), pulse width (ms), repetition rate (Hz) and scan speed (mm/min) were varied. Process parameter optimization was achieved using factorial analysis to investigate the relationship between specific processing parameters and the formation of Waspaloy® specimens. The optimized processing parameters produced Waspaloy® specimens that were 99.7% dense. The resultant laser melted specimen's height, width and contact angles were measured. Specimens were also tested for the occurrence of porosity and observed for microstructure