Surface texture characterization of selective laser melted Ti-6Al-4V components using fractal dimension and lacunarity analysis

Abstract

The Selective Laser Melting (SLM) process based additive manufacturing has wide applications in medical, aerospace, defense, and automotive industries. To qualify the components for certain tribological applications, the characterization of surface texture is very important. But the applicability of traditional methods and parameters to characterize the surface texture were under evaluation. As the nature manufacturing the components were very different and complex, the unconventional surface characterization methods also under evaluation to reveal much more meaningful information. This study demonstrates the surface characterization of Ti-6Al-4V SLM components using fractal analysis of the surface images. The computed fractal dimension using the Fourier transform method showed a strong correlation of more than 0.8 with the measured 3D surface roughness parameters. The change in anisotropic nature of the surface images with the process parameter variation is studied and found that the surface textures showed a weaker anisotropic nature at lower laser power ranges, high scanning speed, and high hatch distance values. The lacunarity analysis is carried out using the gliding box algorithm to study the homogeneity nature of the surface texture and found that the surface texture is more homogeneous at higher surface roughness conditions. The study results can be utilized for the development of a quick, low-cost surface monitoring system in real-time for additive manufacturing industries.

Discrete wavelet transforms analysis of vibration signals for correlating tool wear in diamond turning of additive manufactured Ti-6Al-4V alloy

“…One notable advantage of this AM technique is its ability to directly fabricate intricate lenses or mirrors by customizing the material according to specific requirements [13][14][15] . Akhil et al demonstrated selective laser melting based additive manufacturing surface characteristics using the analysis of surface images 16 . However, AM Ti-6Al-4V ELI alloy is often treated as difficult to machine due to tool wear and generally requires an appropriate selection of process parameters 17 .…”

Study on the forming precision optimization of built-in flow channel structure manufactured by selective laser melting

“…Hence, the SLM forming process has unrivalled advantages in the processing of complex built-in channel structural parts. However, the mechanism of SLM process is extremely complicated due to the effects of many input parameters accompanied by appearance of the different non-equilibrium physical phenomenon, 21,22 the flow channel or the channel structure is still the difficulty to be overcome by SLM forming and receive critical attention. In order to improve the quality of its overhanging surface, by summarizing the scholars' research on metal overhanging structural parts by SLM, the main optimization methods can be divided into two categories: support-assisted structure forming and unsupported optimization.…”