Ramdziah Md. Nasir

The effect of ZnO nanoparticles on the mechanical, tribological and antibacterial properties of ultra-high molecular weight polyethylene:

In this study, the response of different filler loadings (5–20u2009wt%) of zinc oxide nanoparticles reinforced ultra-high molecular weight polyethylene on the mechanical, tribological and antibacterial performances were attempted. The compression, tensile and micro-hardness properties of the nano-zinc oxide/ultra-high molecular weight polyethylene composites were studied. The tribological properties were investigated using DUCOM pin-on-disc tester with variable applied loads (5–35u2009N) and sliding speeds (0.209u2009m/s and 0.419u2009m/s) against 1200 grit size silicon carbide abrasive paper under dry sliding conditions. The worn surfaces and transfer films of the composites were observed using the scanning electron microscopy. Experimental results show that reinforcing ultra-high molecular weight polyethylene with zinc oxide nanoparticles would improve certain mechanical and tribological properties. Wear performance was enhanced with maximum wear resistance found at 10u2009wt% nano-zinc oxide/ultra-high molecular weight polyethylene composite. The average coefficient of friction of ultra-high molecular weight polyethylene shows a decrease after reinforcement with zinc oxide nanoparticles. Upon zinc oxide nanoparticles reinforcement, the worn surface shows reduced severity of wear. The nano-zinc oxide/ultra-high molecular weight polyethylene composite imparts antibacterial activity against Escherichia coli and Staphylococcus aureus.

Microstructural aspects of wear behaviour of TiC coated low alloy steel

A comparison of the room temperature wear behaviour of untreated low alloy steel surfaces with those containing TiC powders was conducted against an alumina ball. The coefficient of friction, the wear rate and the severity of the damage on the surface were assessed. Incorporation of powders produced a hardness 2.6 times greater and a wear rate 21 times less than the untreated steel. Friction from the third body abrasion and protruding carbides of the processed steel resulted in mild wear with a steady state coefficient friction of 0.4. Both samples showed surface chemical reactivity with the environment as a result of the generation of flash temperature producing an oxide layer, which influenced wear.

Thermal and Tribological Properties of Phenolic/CNT-Alumina Hybrid Composites

Carbon nanotube (CNT) reinforced polymer composites are of great interest, because their superior properties can produce composite materials with high strength, light weight, and multifunctional features. In this work, the thermal and tribological properties (wear) of Phenolic/CNT-Alumina Hybrid composites were studied. The CNT-alumina hybrid (chemically hybrid) was produced via Chemical Vapour Deposition (CVD). The Phenolic/CNT-Alumina Hybrid composites were fabricated using hot mounting moulding. The tribological properties were monitored using a Ducom TR-20 pin-on-disk tester, under dry sliding conditions. The thermal conductivity was measured using the Transient Plane Source (TPS) method, using a Hot-DiskTM Thermal Constant Analyzer. The results show that CNT-Alumina hybrid enhanced the thermal and tribological properties of the polymer composites.

Wear behaviour at 600°C of surface engineered low-alloy steel containing TiC particles

ABSTRACT The work aimed to develop surfaces that could resist wear at high temperatures, thus achieving a prolonged component life. Surface modification of a low-alloy steel by incorporating TiC particles has been undertaken by melting the surface using a tungsten inert gas torch. The dry sliding wear behaviour at 600°C of the original and modified surfaces was compared. Microscopic examination of both surfaces showed glazed layers across the wear tracks, with differing amounts of oxide and homogeneity. Extensive wear occurred on the steel surface, which showed deformation of the wear scar tracks and a steadily increased friction coefficient. The TiC addition reduced the wear loss, coinciding with a glazed layer 33% thinner than that on the low-alloy steel sample.

Optimization on Abrasive Wear Performance of Pultruded Kenaf-Reinforced Polymer Composite Using Taguchi Method

This study examined the optimal abrasive wear performance of kenaf-reinforced polymer composite under different sliding conditions. Three different fiber loadings i.e. 43.05, 49.30 and 55.33 vol.% of kenaf fiber was reinforced into a polyester resin using the pultrusion technique. Optimal responses of wear rate and average coefficient of friction (COF) for kenaf fiber-reinforced polyester composites, based on different levels of control factors (fiber loading, applied load, counterface roughness and sliding speed) were determined by the Taguchi Design of experiment (DOE) with L9 (34) orthogonal array and Analysis of variance (ANOVA) methods. The wear behaviour of kenaf fiber-reinforced composites were investigated using DUCOM pin-on-disc tester with three levels of applied loads (10-30 N), sliding speeds (0.42-1.3 m/s) against different grit sizes of silicon carbide abrasive papers (average grain size~2.2-25.2 μm) under dry sliding condition. The optimization of S/N ratio and degree of significance of the control variables to minimize the wear rate and average COF of kenaf fiber-reinforced polyester composites was carry out. The results showed that the counterface roughness is the most significant factor in affecting the wear rate, followed by applied load, sliding speed, and fiber loading. For average COF, the fiber loading is the most significant factor followed by applied load, sliding speed and counterface roughness.

Effect of Pin Size on Reciprocating Sliding Wear Test of Ti-6Al-4V

Ti-6Al-4V is material that has the special characterisation and widely used in tribology studies. In this study reciprocating sliding test between Ti-6Al-4V pin on Ti-6Al-4V flat surface was conclude and focussed on the different contact area of pin size. The testing is run using tribometer pin-on-flat machine where the parameter set on the computer. The sample profilometry than analysed using 3D optical microscope (OM) and value of hardness get from Vickers hardness (HV) test. Due to the experiment, the contact pressure for 6.5 mm is higher than the 12 mm pin size, that brings the higher depth of wear.

Characterisation of Ti-6Al-4V Reciprocating Sliding Wear Test Behaviour

Sliding contact will experience wear in majority of mechanical components during their service life where it reduces the performance of the components. The capability to predict the evolution of reciprocating wear scars, such as the scar’s width and depth, would be a valuable tool when designing mechanical components. Wear scar mechanism behaviour is characterised during stabilized cycle reciprocating sliding wear test of Ti-6Al-4V investigated using pin-on-flat arrangement under variable duration of sliding. The test samples were analyzed using profilometer test, optical microscopy test, Scanning Electron Microscopy (SEM) test, Energy Depressive X-ray (EDX) test and Vickers Hardness (HV) test. Stabilised high number of cycles shows low wear rate and initiation period of low cycles produced higher wear rate.

Characterisation of plasticity response for reciprocating sliding wear test of Ti-6Al-4V under variables number of cycles

Reciprocating sliding wear test of uncoated titanium alloy, Ti-6Al-4V is investigated using pin-on-flat contact arrangement of Ti-6Al-4V/Ti-6Al-4V pair under variable number of cycles at low number of cycles. The worn surfaces of the titanium alloy specimens were analyzed with the use of optical microscope (2D and 3D OM) and Vickers Hardness analysis was carried on. The pattern of the wear scar characteristics determined and the finding at the end of wear track had been focus through the presence at the end of wear track. It is suggesting an evidence of plastic deformation with the increasing in hardness value. The increase in hardness value at the end of wear track indicates increase in the plastic deformation with increasing number of cycles.

Effect of Catalyst Calcination Temperature on the Synthesis of MWCNTs-Talc Hybrid Compound Using CVD Method

Carbon nanotubes-talc (CNTs-talc) hybrid compound has been successfully synthesized via chemical vapour deposition (CVD) method. A gas mixture of methane/nitrogen (CH4/N2) was used as the carbon source and nickel as the metal catalyst for the growth of CNT hybrid compound. Talc works as substrate or support material which is combined with nickel to form a complex metal-talc catalyst that will react with carbon source to produce the hybrid compound. To study the effect of different calcinations temperature, four different calcinations temperature, 300 °C (C-talc300), 500 °C (C-talc500), 700 °C (C-talc700) and 900 °C (C-talc900) were used. Among these four calcination temperatures for synthesis the multi-walled carbon nanotubes (MWCNTs), C-talc500 is the most optimum calcination temperature to perform catalytic decomposition by reacting in methane atmosphere at 800 °C to produce the CNT-talc hybrid compound.

The Effect of Zeolite on the Crystallization Behaviour and Tribological Properties of UHMWPE Composite

In this work, the effects of adding different filler loadings (520 wt%) of zeolite to the ultra-high molecular weight polyethylene (UHMWPE) matrix on the crystallinity behaviour and tribological properties were studied. The zeolite/UHMWPE composites were fabricated using hot compression moulding. The crystallization behaviour was investigated using differential scanning calorimetry (DSC). The tribological properties were monitored using a Ducom TR-20 pin-on-disc tester under different sliding speeds of 0.209 ms-1 and 0.419 ms-1 and with various applied loads of 5, 10, 15, 20, 25, 30 and 35 N. The worn surfaces of the zeolite/UHMWPE composites were observed under the scanning electron microscope (SEM). The results showed that the addition of zeolite into UHMWPE matrix can effectively enhance the percentage crystallinity of the UHMWPE. 15 wt% zeolite-reinforced UHMWPE composites show the increase of 47% in percentage crystallinity as compared to pure UHMWPE. The wear mass loss of the composites was found to be reduced by the incorporation of zeolite in UHMWPE. In addition, the average coefficient of friction (COF) was also found to decrease with the addition of zeolite. The lowest average COF was obtained by 20 wt% zeolite reinforcements into UHMWPE. Shallower grooves and smoother worn surfaces were observed for zeolite/UHMWPE as compared to pure UHMWPE.