Narrow Results

Sliding wear and three-body abrasive wear characteristics of plain carbon steel (0.19C-0.72Mn) were compared to understand mechanisms of both wear in the steel. Microstructure of the steel was varied by heat treatments, and effects of microstructure as well as hardness on both wear were investigated. Dry sliding wear tests were carried out at room temperature using a pin-on-disk wear tester against AISI 52100 bearing steel. Three-body abrasive wear tests were performed using a ball-cratering abrasive wear tester employing angular SiC abrasives. The sliding wear proceeded with subsurface deformation and consequent fracture, while micro ploughing and cutting were major mechanisms of the abrasive wear. Hardness alone failed to characterize the sliding wear of the steel. Subsurface strain-hardening and uniform-deformation were principal controlling factors for the sliding wear, while hardness was the factor to control the abrasive wear of the steel under the given test condition.

Microstructure of WC reinforced Ni-based self-fluxing alloy composite coating sprayed and fused by oxy-acetylene flame was investigated by scanning electron microscopy and energy dispersive X-ray Spectrometry, X-ray diffraction, and transmission electron microscopy. The wear performance of the coating was studied by a MLS-225 wet sand rubber wheel abrasive wear tester at various loads and sizes of abrasive particles. Also, the wear resistance of the coating was compared with uncoated ASTM1020 steel. The results indicated that the coating is bonded metallurgically to the substrate and has a homogeneous microstructure composed of both coarse WC and fine carbide and boride grains such as Cr₇C₃, Cr₂₃C₆, and Ni₂B which disperse uniformly in the matrix of γ-Ni solid solution and Ni₃B. The worn mass loss of the coating and ASTM1020 steel both increased with the load and size of abrasive particles, also, the coating has exhibited excellent abrasive wear resistance compared with ASTM1020 steel.

The aim of this study was to investigate the effect of the surface condition of the coulters of a Poznaniak mechanical seeder working in a sand medium on their abrasive wear resistance. Two types of coulter flap surface treatments were performed. The first treatment method was flame spraying, performed with the use of Eutalloy 10112 powder and other method was laser surface modification consisting in remelting a piece of the coulter flap tip by means of TRUMPF’s CO₂ molecular laser. The study involved the use of a purpose-built laboratory test stand dedicated to testing wear in a sandy medium. The study revealed that surface treatment changes surface microstructure and thus improves its hardness by $1.5$ to 3 times, which translates into two- to six-fold improvement in wear resistance per hectare of cultivated field. Laser surface modification is more economical than thermal spraying and that the coulter flap surface area modified by thermal spraying was much greater than in the case of laser remelting, and finally that the average wear measured as a weight loss of tested coulters was comparable, one can conclude that in the analyzed context laser surface modification will probably prove more efficient than flame spraying. The study showed that there exist ready-to-use technologies for improving operational performance and delaying terminal wear.

Nylon ($N$), Glass-filled nylon (GFN) composites and hybrid graphene oxide blended GFN (GO-GFN) nanocomposites plates were prepared by blending and subsequent injection molding process. Mechanical tests were conducted to study the tensile property, flexural property and hardness of nylon, GFN and GO-GFN system. The fabricated plates were subjected to abrasive wear testing in Pin-on-disc tribometer. The pin used is aluminium oxide (Al₂O₃) ceramic tool. The coefficient of friction, frictional force and loading variations were observed and studied to analyze the susceptibility of nylon, GFN and GO-GFN nanopolymer composites for abrasive wear conditions. This experimental study confirmed the enhancement in the abrasive wear resistance behavior of GO-GFN hybrid nanocomposites.

This paper addresses friction energy-induced reduction of TiO₂ during abrasive wear and friction of alumina–titania coatings with different TiO₂ content. Alumina–13% titania and alumina–40% titania coatings were deposited by atmospheric plasma spray technique. An improvement in fracture toughness and better densification of coatings was observed with an increase in titania content. Alumina–40% titania coating showed lower friction coefficient and higher abrasive wear resistance than alumina–13% titania coating. An increase in friction energy was associated with enhanced reduction of TiO₂ to Ti₂O₃ and an increase in the extent of gamma alumina to alpha alumina phase conversion. These observations along with structural and mechanical properties of coatings could explain differences in tribological response of these coatings. Friction energy parameter (FEP) was used to identify different regimes of wear and degradation mode of coatings.

In order to improve the anti-friction and anti-wear performances of titanium and expand its application in aerospace and aircraft area, a commercially pure titanium grade 2 (TA2) was chosen and treated by compositing surface treatment. Dimple textures were prepared on the titanium surface by laser surface texturing (LST), and then the textured titanium was treated by ion nitriding. Tribological behaviors of the textured titanium and nitrided textured titanium were investigated under abrasive wear on a tribo-tester. The result shows that the anti-friction and anti-wear properties of textured titanium can be greatly improved by 47.1% and 79.3% after nitriding treatment, respectively. In addition, the dimple density has a significant effect on anti-friction and anti-wear behaviors.