The Effect of Salinized Nano ZrO2 Particles on the Microstructure, Hardness, and Wear Behavior of Acrylic Denture Tooth Nanocomposite

The wear of acrylic denture teeth is a serious problem that can change the vertical dimensions of dentures. This study evaluates the effect of adding salinized nano ZrO2 particles on the microstructure, hardness, and wear resistance of acrylic denture teeth. Heat polymerizing polymethyl methacrylate resin was mixed with salinized ZrO2 at concentrations of 5 wt% and 10 wt%. Acrylic resin specimens without filler addition were used as a control group. SEM/EDS analyses were performed and the Vickers’ hardness was evaluated. Two-body wear testing was performed using a chewing simulator with a human enamel antagonist. After subjecting the samples to 37,500 cycles, both height loss and weight loss were used to evaluate the wear behavior. The microstructural investigation of the reinforced-denture teeth indicates sound nanocomposite preparation using the applied regime without porosity or macro defects. The addition of zirconium oxide nanofillers to PMMA at both 5% and 10% increased the microhardness, with values of up to 49.7 HV. The wear mechanism in the acrylic base material without nanoparticle addition was found to be fatigue wear; a high density of microcracks were found. The addition of 5 wt% ZrO2 improved the wear resistance. Increasing the nanoparticles to 10 wt% ZrO2 further improved the wear resistance, with no microcracks found.

Wear behavior of hydroxyapatite reinforced polymer composite for biomedical applications

In medical fields, hydroxyapatite (HA) is used for restoring the human bones and teeth. Nowadays, newer bio composites are being developed to replace the broken or removed teeth in human using hydroxyapatite. The original teeth may be removed from human, due to various reasons such as tooth decay, periodontal disease and gum diseases. Due to the bioactivity property of HA, it helps the tooth to grow. In this work, tribological properties of HA powder reinforced composite are investigated. Three most important factors that affect the properties of the composites were chosen and varied during wear testing of the composites. The HA powder weight %, applied load (P) and sliding distance (SD) were varied on the basis of Taguchi’s experimental design. Analysis of variance (ANOVA) and (Signal to Noise) SN ratio analysis was used to study the influence of each factor on the specific wear rate (SWR). It was concluded that the HA wt. % highly influences the SWR of the composite during pin on disc testing.

Evaluation of Additive Friction Stir Deposition of AISI 316L For Repairing Surface Material Loss in AISI 4340

Additive technologies provide a means for repair of various failure modes associated with material degradation occurring during use in aggressive environments. Possible repair strategies for AISI 4340 steel using AISI 316L deposited by additive friction stir deposition (AFSD) were evaluated under this research by metallography, microhardness, and wear and mechanical testing. Two repair geometries were investigated: groove-filling and surface cladding. The former represents repair of localized grinding to eliminate cracks, while the latter represents material replacement over a larger area, for example to repair general corrosion or wear. The 316L deposited by AFSD exhibited a refined microstructure with decreased grain size and plastic strain, lower strength, and lower hardness than the as-received feedstock. Wear testing by both two-body abrasion and erosion by particle impingement indicated that the wear resistance of the 316L cladding was as good as, or better than, the substrate 4340 material; however, there was some evidence that the resistance to intergranular corrosion was compromised due to the formation of carbides or sigma phase. In both repair geometries, the microstructure of the substrate beneath the deposited material exhibited heat affected zones that appeared to have austenized during the deposition process, and transformed to martensite or bainite during cooling. This report constitutes an initial evaluation of a novel approach to the repair of structural steel components damaged by microcracking, wear or corrosion.

Degradation Analysis of Jute Fiber Reinforced Waste Tile Powder-Filled Polymer Composite on Wear Characteristics

In this study, a polymer composite is made using chemically treated jute fiber and waste floor tile powder as an alternative source for roof tile application. The wear qualities were examined at various ages, and the outcomes were optimized. In order to improve the wetting properties of the jute fiber, it was chemically treated. MINITAB software was used to develop Taguchi method parameters such as jute fiber percentage, waste tile powder percentage, and NaOH chemical treatment using the MINITAB software. It was determined that hardness was the most important characteristic in terms of wear properties after the specimens were subjected to ageing and abrasion wear testing and hardness tests were carried out as per normal protocols. As a result of the waste tile powder addition, the surface and core pore formation rates were reduced and the wear index rates were low. Jute fiber with 15%, 9% tile powder, and 5% NaOH treatment were found to have the lowest wear index of the other specimen compositions tested, according to the wear index. Specimen made with 5% jute fiber addition, 9% tile powder inclusion, and 10% NaOH treatment, on the other hand, had more hardness. Degradation of the fibers and delamination are side effects of the ageing process. The wear resistance of the surface was increased by the use of waste tile powder.

Pengaruh Limbah Beton sebagai Pengganti Agregat Kasar terhadap Kuat Tekan Beton

Concrete is the main material factor in a construction project field that is often used, because concrete has a high compressive strength value so it is very useful for structural buildings to withstand axial forces or compressive forces on the building itself where the structure can be used. for the long term. However, along with the increase in construction development in Indonesia, it has a negative impact on the environment around the construction site because with the rampant construction of this building it will trigger environmental pollution due to the remaining concrete waste from the construction project. On this basis, it encourages the author to conduct research by utilizing waste concrete as a substitute for coarse aggregate for the compressive strength of concrete, by reusing the concrete waste will increase the life of the material from the waste itself. In this study, the materials used were tested first, such as; cement density, silt content, water content, specific gravity absorption, wear testing and sieve analysis on aggregates. Then for the concrete mixture using concrete waste with variations of 0%, 25%, 50%, 75% and 100% of the total weight of coarse aggregate. In this study, the compressive strength at the age of 21 days with a mixture of 0%, 25%, 50%, 75%, and 100% concrete had a compressive strength of 200.92 kg/cm2, 188.83 kg/cm2, 206, respectively. 96 kg/cm2, 177.50 kg/cm2, and 179.01 kg/cm2. Then experienced an average shrinkage of 9.53 kg/cm2 at the age of 28 days. The optimum compressive strength is at 50% mixed variation, with a value of 206.96 kg/cm2 because it has an increase of 3% higher than normal concrete compressive strength with a mixing ratio of 1:2.5:3.5 and a slump value of ±13.25 cm and the dry weight of the concrete is 7.69 kg.

Study and comparison of wear behaviour of Ni-Al2O3 coatings deposited by hot and cold spray

The sliding wear of hot and cold spray nickel-alumina coatings on SA 213-T 91 boiler steel has been evaluated and compared. The investigation was conducted with pin-on-disc apparatus. The wear testing was done by varying normal loads of 30, 40, and 50N at a constant sliding velocity of 1 ms-1. Then another set of experimentation was done at different sliding velocities of 0.5, 1, and 2 ms-1 at a constant normal load of 30 N. This experimentation was designed to study the effect of varying normal loads and sliding velocities on the wear performance of coatings developed with hot and cold spray techniques. The variation of friction coefficient and wear rate with variation in normal loads and sliding velocities were plotted and analyzed. The evaluation of wear mechanisms and characteristics of Ni-Al2O3 coatings is done with the help of weight change measurements and FE-SEM analysis. The wear resistance of hot spray coatings was found better at high normal loads and sliding velocities in comparison to cold sprayed coatings.

Study of the structure and frictional properties of a new composite friction material

В статье приведены результаты исследования фрикционных свойств и структуры нового композиционного фрикционного материала (КФМ). В ходе исследования были разработаны восемь перспективных составов КФМ, полученных методом порошковой металлургии. Фрикционные испытания новых материалов проводились на испытательной машине на трение и износ ИИ5018, оснащённой программным комплексом Tester 3.0, позволяющим точно фиксировать изменение момента трения в течение испытания с построением графика и автоматическим расчётом параметров трения. Методика испытаний позволила имитировать условия фрикционного взаимодействия, возникающие в муфтах электроприводов, применяемых в наземном и морском транспорте. По результатам испытаний оценивались величина коэффициента трения и его стабильность на протяжении цикла испытания и в диапазоне рабочих регулировок электропривода, а также износостойкость КФМ. На основании исследований структуры поверхности трения и качественной оценки стабильности коэффициента трения был определён оптимальный состав КФМ, способный обеспечить стабильную и безопасную работу электропривода в диапазоне рабочих регулировок. The article presents the results of a study of the frictional properties and structure of a new composite frictional material (CFM). In the course of the study, eight promising CFM compositions were developed, obtained by the method of powder metallurgy. Friction tests were carried out on a friction and wear testing machine II5018, equipped with the software package Tester 3.0, which allows registering the change in friction moment during the test with plotting and automatic calculation of friction parameters. The test technique made it possible to simulate the conditions of frictional interaction arising in the couplings of electric drives used in land and sea transport. After the tests, the value of the friction coefficient, its stability during the test cycle and in the range of operating adjustments of the electric drive and the wear resistance of the CFM were evaluated. Based on the analysis of the structure of the friction surface and a qualitative assessment of the stability of the coefficient of friction, the optimal composition of the CFM capable of ensuring stable and safe operation of the electric drive in the range of operating adjustments was determined.

Effect of Current Density and Bath Temperature to The Corrosion and Wear Behaviour of Tungsten Carbide - Nickel Electrodeposition Coating

The composite (ceramic-metal) coating has become a desired coating due to its higher wear and corrosion behaviour compares to metal coating only. This study focuses on the effect of the deposition parameter which is the current density and bath temperature on the corrosion and wear behaviour of the coating. As the current density and temperature will affect the movement of the electron during deposition, it is important to evaluate its effect on the coating thickness and its wear and corrosion performance. The mild steel was used as the substrate and nickel-tungsten carbide (Ni-WC) as the coating. Watts’s bath was used as an electrolyte with the addition of 25 g/l WC. 0.2 A/cm2 and 0.5 A/cm2 has been chosen as the current density while 30 °C and 50 °C as their temperature. The coating was characterised using a scanning electron microscope (SEM) and x-ray diffractometer (XRD). Immersion test and weight loss test was used to evaluate the corrosion and wear behaviour respectively. The 3 g/l silicon carbide was used as abrasive materials in the wear testing. Vickers micro-hardness tester was used for hardness property evaluation. It is found that higher current density and higher bath temperature results in lower corrosion and wear rate which shows higher resistance.

WEAR CHARACTERIZATION OF LM29 ALLOY WITH40 MICRON SIZED B4C REINFORCED METAL COMPOSITES

This paper deals with the fabrication and evaluation of wear properties by introducing40 micron size B4C particulates into LM29 alloy matrix. LM29 alloy based metal matrix composites were prepared by stir casting method. 3, 6 and 9 wt. % of 40 micron sized B4C particulates were added to the base matrix. For each composite, the reinforcement particles were pre-heated to a temperature of 600 degree Celsius and then dispersed in steps of two into the vortex of molten LM29 alloy to improve wettability. The Micostructural study was done by using Scanning Electron Microscope (SEM), which revealed the uniform distribution of B4C particles in matrix alloy, EDS analysis confirmed the presence of B4C particles in the LM29 alloy matrix.A pin-on-disc wear testing machine was used to evaluate the wear loss of prepared specimens, in which a hardened EN32 steel disc was used as the counter face. The results revealed that the wear loss was increased with increase in normal load and sliding speed for all the specimens. The results also indicated that the wear loss of the LM29-B4C composites were lesser than that of the LM29 matrix. The worn surfaces and wear debris were characterized by SEM microanalysis.

Modification of a simplified hip joint simulator into an ISO 14242-1 compliant design and a comparison of wear test results

The ISO 14242-1 standard for hip joint simulator wear testing specifies a set of test conditions for the simulation of normal level walking in optimal conditions. Since some of the established simulators, such as the 12-station HUT-4, are not ISO 14242-1 compliant, the present study was carried out to answer the following question. Does wear produced in ISO 14242-1 conditions differ from that obtained earlier with the simplified HUT-4 hip joint simulator for similar specimens in normal level walking, optimal conditions? The HUT-4 hip joint simulator was made ISO compliant by an implementation of a number of modifications. One of the modifications was the design and construction of a novel servo-electric load actuator with proven dynamic response. The other modifications were related to the Euler sequence of motions, acetabular abduction angle, enclosure of the lubricant chamber, and temperature control. A 5 million-cycle wear test with thin, large-diameter VEXLPE liners resulted in a wear rate close to that obtained earlier with the HUT-4. The burnished bearing surface in both tests was in agreement with clinical retrieval studies. It appeared that a more simple, inexpensive hip joint simulator can reproduce clinical wear mechanisms. However, the simulator must meet certain basic requirements, such as the correct type of multidirectional relative motion, for which biaxial motion is sufficient. The present study was not intended to show a similarity in wear produced by the ISO 14242-1 and HUT-4 wear test systems.