Huseyin Imrek

Examination of Pitting and Wear in Borided, Carburized, and Borocarburized AISI 8620 Gears

The most important characteristic feature of boronizing is that the boron layer obtained at the surface has a very high hardness, improved wear resistance, and low coefficient of friction. Due to the sudden transition from a very hard surface to a relatively soft core, cracks are likely to occur at the interface. These cracks may lead to spalling, and therefore the advantageous effects of boronizing are limited under heavy loads. In this study, the pitting and wear behavior of spur gear surfaces of AISI 8620 steel treated by carburizing, boronizing, and borocarburizing have been examined.

Optimization of Test Parameters That Influence Erosive Wear Behaviors of Glass Fiber-Reinforced Epoxy Composites by Using the Taguchi Method

This study describes the development of a multicomponent composite system consisting of thermoplastic epoxy resin reinforced with E-glass fiber and silicon dioxide (SiO2) particles and investigates its erosion behavior under different operating conditions. Due to the increasing importance of composites in engineering applications and the need to tackle solid particle erosion in various industrial sectors, the study aims at finding how these composites behave in such type of wear. The composite specimens used for the tests were classified into three types; pure glass fiber (GF)‐epoxy, those with addition of SiO2 particles at an amount of 15% and the last group had SiO2 particles added at 30% of the resin used for the materials. The experiments were carried out by selecting three different impact velocities, three different impingement angles, and angular alumina abrasive particles having approximate sizes of 200 lm. The fiber directions used were 0/90/0 and 45/ � 45/45. SEM views belonging to the specimens were taken before and after the tests in order to investigate the differences and the causes of the surface damages. Moreover, it is found that the Taguchi’s robust orthogonal array method provides a simple, systematic, and efficient methodology for the optimization of the erosion wear parameters. At the end of the tests, the most significant factor in affecting the erosion rate is found to be the impingement angle, followed by the impact velocity, fiber direction, and filler material. [DOI: 10.1115/1.4028226]

Solid Particle Erosion as Influenced by Tensile Axial Loads

In this study, the effects of external loads and impingement angle on erosive wear of AISI 1010 steels were investigated. Tensile axial loads corresponding to 0, 20, 40, and 60% of the specimen materials yield strength were applied on specimens attached to a specially designed specimen holder. The erosion tests were conducted at impact angles of 15, 30, 45, 60, 75, and 90° for each loading. Particles with angular geometry were used as abrasive steel grits and their impact velocities were adjusted by changing air pressure. The impact velocity of the particles was set at 30 m/s. Graphs of erosion rates as a function of stress and impact angles were constructed based on specimens’ weight loss obtained at the end of the tests. It was found that there was a slightly increase in erosion rate as a result of increased tensile stress. It was also found that the erosion rate increased between 0 and 30°, whereas between 30 and 90° impingement angles, the erosion rate was seen to fall.

Erosion wear performance of borax filled novel hybrid composites by using the Taguchi experimental design

Purpose – This study aims to examine solid particle erosion behavior of novel hybrid composite materials where borax (B2O3) particles (∼150 μm) were added to glass fabric and epoxy resin at an amount of 15 and 30 per cent. Design/methodology/approach – The tests that involved slightly rounded and irregular Al2O3 particles having two erodent sizes (200, 400 μm) were conducted at these operational conditions; namely, three impact velocities (23, 34, 53 m/s), two fabric directions (0/90/0, 45/−45/45) and three impingement angles (30°, 60°, 90°). In addition, the design of experiments, which utilizes Taguchi’s robust orthogonal arrays approach, was used and an optimum parameter combination was established, which had a minimum erosion rate. Moreover, scanning electron microscope and X-ray diffraction views show the visual effect of filler material. Findings – All test specimens regardless of their dissimilar characteristics displayed maximum erosion rate at 30° impingement angle. Test specimens with 45/−45/45 ...

Solid particle erosion behaviour of glass mat-based polyester laminate composite materials:

In this study, solid particle erosion behaviour of glass fibre mat-based polyester laminate composite materials was investigated by varying the impact velocity and the impingement angle and sizes of the abrasive particles. Impact velocities used in the tests were 23, 34 and 53 m/s, while the impingement angles were 15°, 30°, 45°, 60°, 75° and 90°. Silicon dioxide particles with average diameters of 250, 500 and 1000 μm were used as abrasive particles. Experimental data were taken as reference and values of erosion rates were obtained as functions of impact velocity, impingement angle and the size of the abrasive particles. The results obtained exhibited typical ductile behaviour of glass fibre-reinforced composites, where the maximum erosion rate was recorded at an impingement angle of 30°, and the erosion rates decreased as the impingement angle increased. Moreover, the erosion rates increased with the increase in impact velocity and particle size. Finally, the worn out surfaces of the test specimens were investigated on two different devices, optical microscope and scanning electron microscope.

Erosive Wear of Glass Fiber and B2O3 Reinforced Epoxy Composites

In this experimental study, erosive wear behavior of epoxy-resin dipped composite materials reinforced with glass fiber and B2O3 (borax) under different impact velocities, erodent sizes, and erodent striking angles along the fiber direction were investigated. The tests which involved slightly rounded and irregular silicon oxide (SiO2) particles having two different sizes of approximately 250 and 500 , were conducted at two different impact velocities of approximately 20 m/s and 40 m/s, two different fiber directions (0o and 45o) and six different impingement angles of 15o, 30o, 45o, 60o, 75o and 90o. In the test results, erosion rates were obtained as functions of impact velocities, striking angles, fiber direction and particle sizes. In addition, the microscopic views showing worn out surfaces of the glass fiber reinforced epoxy composites were scrutinized.

Solid Particle Erosion Wear of GF/EP Composites with Added Al2O3

This study has targeted to investigate wear behavior of a sort of new composite material where Al2O3 (≈150 μm) particles were added to glass fiber and epoxy resin (GF/EP) at an amount of 15% and 30%. The method used in the tests, was the one that use dry and compressed air to accelerate abrasive particles onto a specimen and from there the wear formed was investigated. Striking speed was determined with the help of a double disc method by making use of pressure difference, whereas impinging angles were set by turning the specimen holder around its axis. As a result, in this experimental study, solid particle erosion behavior of a new formed composite material was investigated and erosion rates computed where three different impinging angles (30°, 60° and 90°), three different striking speeds (23, 34 and 53 m/s) and two different fiber directions (0° and 45°) were used to enable angular aluminum abrasives with average diameter of 400 μm to bombard target specimens to undertake the tests. In addition, the s...