Wettability and Surface Roughness Analysis of Laser Surface Texturing of AISI 430 Stainless Steel

Abstract

Due to its wide applicability in industry, devising microstructures on the surface of materials can be easily implemented and automated in technological processes. Laser Surface Texturing (LST) is applied to modify the chemical composition, morphology, and roughness of surfaces (wettability), cleaning (remove contaminants), reducing internal stresses of metals (hardening, tempering), surface energy (polymers, metals), increasing the adhesion (hybrid joining, bioengineering) and decreasing the growth of pathogenic bacteria (bioengineering). This paper is a continuation and extension of our previous studies in laser-assisted texturing of surfaces. Three different patterns (crater array-type C, two ellipses at 90° overlapping with its mirror-type B and 3 concentric octagons-type A) were applied with a nanosecond pulsed laser (active medium Nd: Fiber Diode-pumped) on the surface of a ferritic stainless steel (AISI 430). Micro texturing the surface of a material can modify its wettability behavior. A hydrophobic surface (contact angle greater than 90°) was obtained with different variations depending on the parameters. The analysis performed in this research (surface roughness, wettability) is critical for assessing the surface functionality, characteristics and properties of the stainless steel surface after the LST process. The values of the surface roughness and the contact angle are directly proportional to the number of repetitions and inversely proportional to the speed. Recommendations for the use of different texturing pattern designs are also made.

Morphological Analysis of Laser Surface Texturing Effect on AISI 430 Stainless Steel

“…Two hundred shots were applied to each of the samples, with a power density of ~2 × 10 7 W/cm 2 . The results obtained and the related conclusion that the laser fluence is directly influenced by ablation, is consistent with the results obtained in relation with this research and presented in a previous paper of Moldovan E. et al [24].…”

“…For example, for polymers it is between 0.1 to 1 J/cm 2 , while for inorganic insulators it is between 0.5 and 2.0 J/cm 2 [2]. Related to the present study, Moldovan E. et al [24] showed a decrease in fluence values from 8.49 J/cm 2 to 2.55 J/cm 2 , in the frequency range of 30-100 kHz. The materials have a different behavior under the action of the laser.…”

“…The spot size in the nanosecond case was 163 µm (compared to 100 µm in the current study). All parameters can be analyzed comparatively in the papers [24][25][26]. SEM analysis shows uniform Mg matrix with dispersed Al-Mn-Fe particles.…”

“…Experimental research has generally shown better results in picoseconds and femtoseconds laser, but the encouraging results in the case of nanoseconds, and especially the applications for industrial and economic reasons, determined our choice in the study of the latest technical solution. The goal is to perform the morphological and elemental analysis of the laser surface texture patterns on AISI 430 stainless steel, continuing the studies completed in [24,26] for geometry, wettability, and roughness characterization.…”

Effect of Different Laser Groove Texture Collation Frequency on Tribological Properties of 0Cr17Ni7Al Stainless Steel

“…The friction characteristics of the surface can be effectively improved by machining the texture with regular geometric dimensions and an orderly arrangement on the part surface. Surface modification has been widely used in many fields; for example, in the field of material surface friction reduction [2][3][4] and friction pair surface wear resistance [5,6], on some special occasions where surface friction needs to be increased [7], in environments where the system needs to reduce vibration [8][9][10], in the special field of resistance to adhesion [11], in the special environment of anti-creep [12], with long-term low-temperature equipment [13], and when the equipment needs to increase the bearing capacity [14], in the field of maintaining wettability [15], as well as areas with functional hydrophobicity requirements [16] and scenarios with increased adhesion [17]. It has shown good application prospects and become an effective way to achieve the high efficiency, miniaturization and high reliability of mechanical equipment [18].…”