Enhanced mar/scratch resistance in automotive clear coatings by modifying crosslinked polyurethane network with branched flexible oligomers

This work presents fundamental understanding of the correlation between nanoindentation hardness and practical scratch resistance for mechanically tunable anti-reflective (AR) hardcoatings. These coatings exhibit a unique design freedom, allowing quasi-continuous variation in the thickness of a central hardcoat layer in the multilayer design, with minimal impact on anti-reflective optical performance. This allows detailed study of anti-reflection coating durability based on variations in hardness vs. depth profiles, without the durability results being confounded by variations in optics. Finite element modeling is shown to be a useful tool for the design and analysis of hardness vs. depth profiles in these multilayer films. Using samples fabricated by reactive sputtering, nanoindentation hardness depth profiles were correlated with practical scratch resistance using three different scratch and abrasion test methods, simulating real world scratch events. Scratch depths from these experiments are shown to correlate to scratches observed in the field from consumer electronics devices with chemically strengthened glass covers. For high practical scratch resistance, coating designs with hardness >15 GPa maintained over depths of 200–800 nm were found to be particularly excellent, which is a substantially greater depth of high hardness than can be achieved using previously common AR coating designs.

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Mathematical modelling and optimization of laser beam parameters on microhardness and surface scratch resistance of Al-TiZn alloy

Advances in Materials and Processing Technologies ◽

10.1080/2374068x.2020.1860502 ◽

2021 ◽

pp. 1-16

Author(s):

Moera Gutu Jiru ◽

Devendra Kumar Sinha ◽

Habtamu Beri

Keyword(s):

Laser Beam ◽

Mathematical Modelling ◽

Scratch Resistance ◽

Beam Parameters ◽

Modelling And Optimization

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Evaluation of Abrasive Wear of Polymeric Materials Using Single-Pass Pendulum Scratching

21st International Conference on Offshore Mechanics and Arctic Engineering, Volume 3 ◽

10.1115/omae2002-28250 ◽

2002 ◽

Author(s):

Marcelo Torres Piza Paes ◽

Antonio Marcos Rego Motta ◽

Lauro Lemos Lontra Filho ◽

Juliano Ose´ias de Morais ◽

Sine´sio Domingues Franco

Keyword(s):

Deep Water ◽

Wear Mechanisms ◽

Degradation Mechanism ◽

Single Point ◽

Polymeric Materials ◽

Scratch Resistance ◽

Wear Behaviour ◽

Sediment Layer ◽

Materials Used ◽

Energy Dissipated

Scratching abrasion due to rubbing against the sediment layer is an important degradation mechanism of flexible cable in deep water oil and natural gas exploitation. The present study was initiated to gain relevant data on the wear behaviour of some commercial materials used to externally protect these cables. So, Comparison tests were carried out using the single-point scratching technique, which consists of a sharp point mounted at the extremity of a pendulum. The energy dissipated during the scratching is used to evaluate the relative scratch resistance. The results showed, that the contact geometry strongly affects the specific scratching energy. Using SEM imaging, it was found, that these changes were related to the operating wear mechanisms. The observed wear mechanisms are also compared with those observed on some cables in deep water operations.

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Effects of Pre- and Post-Carburizing Surface Modification on the Tribological and Adhesion Properties of Heat-Resistant KHR 45A Steel for Cracking Tubes

Materials ◽

10.3390/ma14133658 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3658

Author(s):

Auezhan Amanov ◽

Joo-Hyun Choi ◽

Young-Sik Pyun

Keyword(s):

Surface Modification ◽

Surface Treatment ◽

Steel Substrate ◽

Heat Exposure ◽

Scratch Resistance ◽

Adhesion Properties ◽

Heat Resistant ◽

Adhesion Behavior ◽

Steel Substrates ◽

Carburizing Process

In this study, the effects of ultrasonic nanocrystal surface modification (UNSM) technology on the tribological properties and scratch-induced adhesion behavior of a heat-resistant KHR 45A steel cracking tube, which is used for the pyrolysis process, were investigated. The main objective of this study is to investigate the effects of pre- and post-carburizing UNSM treatment on the tribological and adhesion performances of carburized domestic KHR 45A (A) steel and to compare the results with the existing carburized Kubota-made KHR 45A steel (B). A carburizing process was carried out on the polished and UNSM-treated KHR 45A steel substrates, which were cut out from the cracking tube, at 300 °C heat exposure for 300 h. The thickness of the carburizing layer was about 10 μm. UNSM technology was applied as pre- and post-carburizing surface treatment; both reduced the friction coefficient and wear rate compared to that of the carburized KHR 45A steel substrate. It was also found that the application of UNSM technology increased the critical load, which implies the improvement of adhesion behavior between the carburizing layer and the KHR steel substrate. The application of UNSM technology as pre- and post-carburizing surface treatment could help replace carburized Kubota-made KHR 45A steel (B) thanks to the improved tribological performance, enhanced scratch resistance, load bearing capacity, and adhesion of domestic KHR 45A (A) steel.

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Biomimetic Transparent Eye Protection Inspired by the Carapace of an Ostracod (Crustacea)

Nanomaterials ◽

10.3390/nano11030663 ◽

2021 ◽

Vol 11 (3) ◽

pp. 663

Author(s):

Andrew R. Parker ◽

Barbara P. Palka ◽

Julie Albon ◽

Keith M. Meek ◽

Simon Holden ◽

...

Keyword(s):

Elastic Modulus ◽

Thin Film Deposition ◽

Dielectric Materials ◽

Scratch Resistance ◽

Film Deposition ◽

Original Form ◽

Biomimetic Material ◽

Eye Protection ◽

Protection Coating

In this study we mimic the unique, transparent protective carapace (shell) of myodocopid ostracods, through which their compound eyes see, to demonstrate that the carapace ultrastructure also provides functions of strength and protection for a relatively thin structure. The bulk ultrastructure of the transparent window in the carapace of the relatively large, pelagic cypridinid (Myodocopida) Macrocypridina castanea was mimicked using the thin film deposition of dielectric materials to create a transparent, 15 bi-layer material. This biomimetic material was subjected to the natural forces withstood by the ostracod carapace in situ, including scratching by captured prey and strikes by water-borne particles. The biomimetic material was then tested in terms of its extrinsic (hardness value) and intrinsic (elastic modulus) response to indentation along with its scratch resistance. The performance of the biomimetic material was compared with that of a commonly used, anti-scratch resistant lens and polycarbonate that is typically used in the field of transparent armoury. The biomimetic material showed the best scratch resistant performance, and significantly greater hardness and elastic modulus values. The ability of biomimetic material to revert back to its original form (post loading), along with its scratch resistant qualities, offers potential for biomimetic eye protection coating that could enhance material currently in use.

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