Laser micromachining of TiN coatings with variable pulse durations and shapes in ns regime

Demir, Ali Gökhan; Pangovski, Krste; O’Neill, W; Previtali, Barbara

doi:10.1016/j.surfcoat.2014.09.021

Cited by 18 publications

(11 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…For more complex multiple pulse interactions, the accumulation of heat can be expected, hence resulting in reduced machining quality. As demonstrated previously, on the same material the pulses similar to the present 30 ns, where τ=12 ns (FWHM) exhibited melt free ablation with multiple pulses [8]. Moreover, damage accumulation behaviour, a phenomenon that reduces the ablation threshold as a function of pulse number commonly with ultrashort pulses [36] was observed.…”

Section: Recommendations For Pulse Shape Designsupporting

confidence: 83%

See 1 more Smart Citation

Investigation of pulse shape characteristics on the laser ablation dynamics of TiN coatings in the ns regime

Demir¹,

Pangovski²,

O’Neill³

et al. 2015

J. Phys. D: Appl. Phys.

Self Cite

View full text Add to dashboard Cite

In this work, the ablation dynamics of TiN coating with a ns-pulsed fibre laser in a wide range of pulse durations were studied. Critical time instances within the pulse duration were assessed by reflected pulse analysis. Digital holography was employed to investigate the shock wave expansion dynamics within and beyond the pulse duration. The results depict that the absorption behaviour changes as a function of the pulse rise time. Moreover, planar expansion of the shock wave is observed, which is generally linked to higher machining quality and absence of excessive plasma. The results of the study are interpreted to depict the required characteristics of optimized pulse shapes in ns-region for improved micromachining performance.

show abstract

Section: Recommendations For Pulse Shape Designsupporting

confidence: 83%

“…On the other hand, ns-pulsed laser ablation of TiN coatings was studied in single and multiple pulses previously [8]. The effects of pulse peak and tail have been shown on the ablation quality and efficiency empirically.…”

Section: Introductionmentioning

confidence: 99%

Investigation of pulse shape characteristics on the laser ablation dynamics of TiN coatings in the ns regime

Demir¹,

Pangovski²,

O’Neill³

et al. 2015

J. Phys. D: Appl. Phys.

Self Cite

View full text Add to dashboard Cite

show abstract

“…As one wear-resistant coating, the coefficient of friction and wear rate of TiN films are high under dry friction conditions. Efforts to improve the tribological properties of TiN have included changed deposition parameter and doped chemical elements during the film preparation [2][3][4][5], surface treatments, and modifications during film post-processing [6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Effects of Different Materials on the Tribological Performance of PVD TiN Films under Starved Lubrication Regime

Jiang¹,

Gao²,

Hu³

et al. 2018

Lubrication - Tribology, Lubricants and Additives

View full text Add to dashboard Cite

Grit blasting is one simple but effective method to modify the morphology of material surface and can improve the tribological performance. In this study, a thick TiN film was prepared by arc ion plating on the steel disk treated with grit blasting, and the rough surface coated solid film was obtained. The tribological properties of solid film against different materials were evaluated under starved lubrication regime. The results showed that the friction coefficients of rough titanium nitride (TiN) films were lower than those of rough steel disks exclude alumina ball under starved lubrication, and the wear rates of TiN film were negligible due to the high hardness of TiN film and small contact area. For four kinds of balls including steel ball, silicon nitride, zirconia, and alumina, the wear scar diameter of steel ball is biggest, and the wear scar diameters of other balls are small. The hardness of steel ball is less than others, which results in the easy abrasion and increases the contact area to reduce the pressure. So the friction coefficient of TiN against steel is low and steady.

show abstract

“…The applied coating layer is characterized by limited thickness, in the order of 2-15 μm. When the machining depth exceeds the coating thickness, the ablation conditions change drastically since the steel substrate behaves differently during the interaction with the laser beam [2]. Particularly in percussion drilling, molten steel from the substrate is deposited at the entrance of the blind hole.…”

mentioning

confidence: 99%

“…Particularly in percussion drilling, molten steel from the substrate is deposited at the entrance of the blind hole. For laser surface texturing in view of friction applications, where a great number of microholes are realized over large areas to make a reservoir of solid or liquid lubricant [3], substrate reach can cause coating failure [2]. Thus, online monitoring capabilities are required to overcome process variations during the machining of large area components.…”

mentioning

confidence: 99%

Evaluation of Self-Mixing Interferometry Performance in the Measurement of Ablation Depth

Demir

Colombo

Norgia

et al. 2016

IEEE Trans. Instrum. Meas.

Self Cite

View full text Add to dashboard Cite

Abstract-This paper studies self-mixing interferometry (SMI) for measuring ablation depth during laser percussion drilling of TiAlN ceramic coating. The measurement performance of SMI was investigated in a large processing range producing blind microholes with depths below and beyond the average coating thickness. Signal characteristics of the measurement system were evaluated indicating sources of disturbance. The SMI measurements were compared with a conventional measurement device based on focus variation microscopy to evaluate the measurement error. The measurement error classes were defined, as well as defining the related error sources. The results depict that the measurement error was independent of the processing condition, hence the hole geometry and ablation rate. For 76% of cases, measurement error was below the intrinsic device resolution obtainable by simple fringe counting of half a wavelength (λ/2 = 0.393 μm).

show abstract

Laser micromachining of TiN coatings with variable pulse durations and shapes in ns regime

Cited by 18 publications

References 25 publications

Investigation of pulse shape characteristics on the laser ablation dynamics of TiN coatings in the ns regime

Investigation of pulse shape characteristics on the laser ablation dynamics of TiN coatings in the ns regime

Effects of Different Materials on the Tribological Performance of PVD TiN Films under Starved Lubrication Regime

Evaluation of Self-Mixing Interferometry Performance in the Measurement of Ablation Depth

Contact Info

Product

Resources

About