Water-lubricated pin-on-disc tests with natural fibre reinforced matrix / Ramdziah Md. Nasir

In this study, natural fibre such as paddy straws and cockle shell was chosen due to its abundance and renewable natural fibre reinforced matrix. The fibres were reinforced with polymer using conventional compression molding. The specimen lubricated with water, were slided at different sliding speed using the rotating pin-on-disc friction and wear tests. The best performance under lubricated boundary condition was found for bio-shell cockle reinforced matrix followed by paddy-straw reinforced matrix while pure polypropylene has the highest wear rate and coefficient of friction. With the addition of cockle shell powders or paddy straw, wear rate and coefficient of friction of the material decreases with a minute degree of changes in their properties. The wear mechanism was identified using SEM

Investigation on the Tribological Behaviour of Modified Jatropha Oil with Hexagonal Boron Nitride Particles as a Metalworking Fluid for Machining Process

Bio-based oil from vegetable oils was recently explored as an alternative solution to petroleum-based oil. However, the application of vegetable oils as metalworking fluids (MWFs) for machining process is still not widespread. The objective of this study was to investigate the tribological behaviour of modified vegetable oils, in comparison with synthetic ester (SE) and crude jatropha oil (CJO). In this study, the CJO was chemically modified via transesterification process to develop modified jatropha oil (MJO5). MJO5 was then blended with the hexagonal boron nitride (hBN) particles at various concentrations ranging between 0.05 to 0.5wt.%. The friction and wear test was performed using four ball tribotester. An experiment on orthogonal cutting process was carried out to evaluate the machining performances in terms of cutting force, cutting temperature, chip thickness and tool-chip contact length. The results reveal that the mixture of 0.05wt.% of hBN particles in the MJO5-based oil (MJO5a) outperformed the SE in terms of friction and wear. MJO5a showed excellent machining performances by reducing the machining force and temperature, which related to the formation of thinner chips and small tool-chip contact length. MJO5a is the best substitute to SE as sustainable MWFs in the machining operation with regards to the environmental and health concern

A Study on the Effect of Multistage Toolpath in Fabricating a Customized Cranial Implant in Incremental Sheet Metal Forming

Incremental sheet forming (ISF) process offers a high degree of flexibility in the manufacturing of different sheet parts, which makes it an ideal candidate for prototype parts as well as efficient at fabricating various customized products at low production costs compared to traditionally used processes. However, parts produced in this process exhibit notable geometrical inaccuracy and considerable thickness reduction. In this paper, the single point incremental sheet forming variant of the process has been implemented to manufacture a highly customized cranial implant starting from the computed tomography (CT) scan data of the patient's anatomy. A methodology, from the modeling to the realization of the implant, is presented and discussed. The primary aim of the research was to analyze and study the effect of the multistage toolpath strategy compared to the traditional single-stage toolpath in terms of geometrical accuracy and thickness distribution. The final results show that the part formed in the multistage toolpath strategy exhibited a more uniform thickness distribution compared to the single-stage approach. Regarding the geometrical accuracy, the deviation analysis between the nominal and actual data has revealed that the multistage forming has significantly enhanced the final geometrical accuracy of the formed part

On The Tribological Performance Of Modified Industrial Rubber (DPNR And Polyisoprene)

This study describes how this techniques can be used to highlight the differences in the carbon black loading, blending compound in influencing the tribological behavior and also to show these effect can be used to predict wearing and friction distribution on rubber surface on a more quantitative level. The main objective of this work is to develop and modify industrial rubber, i.e. deproteinised natural rubber (DPNR) and synthetic polyisoprene (PIR). Secondly, to understand the physical, mechanical and tribological properties of these materials as influenced by the addition of soft and hard carbon black (CB), specifically the role of C-black in improving the friction and wear characteristics

Dry sliding wear behaviour of talc-reinforced UHMWPE composite for implant application

As of today, ultra-high molecular weight polyethylene (UHMWPE) is a thermoplastic material normally used as bearing components for human joint replacements. However, formation of wear debris from UHMWPE after certain service periods may cause adverse effects which remain as unresolved issues. In this study, mechanical and dry sliding wear properties of UHMWPE reinforced with different loading of talc particles were investigated. The wear test was carried out using Ducom TR-20 pin-on-disc tester at different pressure velocity (pv) factors under dry sliding conditions. The worn surfaces and transfer films of pure UHMWPE and talc/UHMWPE composites were observed under scanning electron microscope (SEM). The experimental results showed that the microhardness increased with the increase of talc loadings in UHMWPE. The 20 wt. % talc/UHMWPE composites showed a 17% increment in microhardness as compared with pure UHMWPE. The dry sliding wear behaviour of UHMWPE was also improved upon the reinforcement of talc. The wear rate of UHMWPE decreased after incorporation of talc particles. The coefficient of friction (COF) increased slightly under low pv conditions. At high pv conditions, the COF decreased in values with increasing talc loadings. The improvement in wear behaviour may be attributed to the increase in load-carrying capacity and surface hardness of the talc/UHMWPE composites. SEM micrographs on worn surfaces showed that plastic deformation and grooving wear were dominant for UHMWPE. The plastic deformation and grooving wear were reduced upon the reinforcement of talc particles. The talc/UHMWPE composites produced smoother and uniform transfer films as compared to pure UHMWPE

An overview on the importance of surface modification by TIG and lasers incorporating carbides and their relations to wear behaviours

Surface modification is a technique via induction of high energy input to produce a hard resilient thin layer on the surface of the weak substrate. Despite by lasers capable to produce surface modified structures, their vehement cost of manufacturing is not comparable to the TIG torch melting technique which can develop similar quality surface with less cost. To the extent of author’s knowledge, the constant degradation of metal surfaces during friction are most likely to use wear test analysis in order to assess the durability of the coatings. This work takes another important step in discussing the importance of surface modifications at high energy inputs via incorporating reinforcing material by improvising micro-hardness property and finding relationship with wear behavior of the surface modified materials. Several issues on the wear behaviour of coatings mainly from the effect of surface hardness and those without coating with regard to their applications were highlighted. Periodical wear which the author’s enthusiast as a fresh niche area of wear wasn’t that much being explored; hence, explanation was extended at the end of this paper

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