In this work, aluminium foams with modified geometry were successfully fabricated with a combination of dense and porous structure The main objective of this study were to determine the initial physical properties of aluminium foam with modified geometry in terms of density, porosity and morphology. Three different NaCl space holder sizes ranging from 1 mm to 3 mm were sieved and used to replicate the final pore size of aluminium foam. The samples were successfully produced through casting replication process. After densification, samples underwent water leaching in ultrasonic bath to remove completely the space holder. Results showed that porosity of the aluminium foam increased from 50 – 62% when the size of space holder was increased from 1 mm to 3 mm. The morphology showed clearly an integrated modified geometry between dense and inter-connected porous structure which is beneficial for applications that require combination properties of structural, thermal and mechanical properties.
Service Advisor in Automotive Service Centre plays an important role as the frontline in providing exceptional services. The automotive service centre has to adopt big data applications in understanding customers' needs by collecting data promptly and analysing scientifically. The objective of this paper is to evaluate Customer Satisfaction (CS) and Service Advisor Experience (SAE) scores via an online survey based on big data analytics. Thus, applying a Quadrifid graph in identifying focus regions for improvement activities. The application of big data online survey platforms is an efficient way of gathering customer feedback for continuous improvement activities. The study focused on Service Advisor (SA) services throughout Malaysia with selected one automotive brand. It explains the definition of customer process and customer satisfaction by comparing high-density customer regions namely Central, Northern and Southern regions with low-density customer regions namely East Coast and East Malaysia regions. There are five steps in deriving the output, which are the consolidation of customer data, customer selection, survey execution, score calculation and analytical report. Thus, the big data applications analyse the expectation SA gap and propose recommendation actions. The online survey results achieved a minimum of 879.90 points for Customer Satisfaction while Service Advisor Experience was minimum at 73%. SA achieved a high score for portraying courtesy and professionalism, while a lack of performing the visual inspection is the main gap for all regions. Detailed analysis using Quadrifid graph interpreted Southern region recorded the lowest correlation with R-square value less than 0.1 and level of CS & SAE below the average value of 800 relates to response towards needs by SA. In this paper, the outcome of the execution is centralization of customer information, Service Level Agreement standard, customer handling norms and work efficiency improvement. Such indicators lead to the SA's professionalism in managing customer expectations.
Sandwich panels are widely used in the fabrication of high strength low-weight structure that can withstand impact and blast loading especially for aerospace and automotive structures. Currently, aluminium foam is one of the lightweight materials used as a core in sandwich panels. The combination properties of core and face-sheet material are important to produce high strength and lightweight sandwich panel. This research is aimed to develop a carbon fibre reinforced polymer (CFRP) composite sandwich panel with aluminium foam as a core and study the impact properties of the structure. The preparations of the sandwich panel involved closed-cell aluminum foam as a core material and CFRP composite as the face-sheets. The impact tests were conducted using an Instron Dynatup 9250HV impact tester machine according to ASTM standard D3763 under constant impact velocity of 6.7m/s. The results of the impact tests showed that CFRP composite sandwich panel has better impact properties when compared to the other systems where it has higher specific energy absorption and longer impact time.
Carburizing temperature plays an important role for carbon to disperse deep inside the steel surface. Pack carburizing requires higher temperatures to disperse the carbon compared to gas carburizing and bed carburizing. Introduction of different carburizing media (powder and paste compound) might contribute toward the effectiveness of this process. This paper investigates on the effect of different temperature (700oC-1000oC) using powder and paste compound towards the carbon dispersion in carburized steel. Mild steel was used as the substrate material which has been carburized using the powder and paste compound with a ratio of 1:1 and 3:1,respectively. The temperatures has been set at 700oC, 800oC, 900oC and 1000oC for 8 hours. The effects of carbon dispersion layers were observed by the increasing depth of case hardness. The chemical composition analysis was done by using a spectrometer to see the increment of carbon content of the carburized steel. Results showed that the paste compound at a temperature of 1000oC significantly influenced the hardness properties and carbon composition as compared to the carburized steel obtained from the powder compound.
Stainless steel is used widespread in various industries, but it has poor wear resistance. Therefore, this study aims to investigate the wear resistance of enhanced surface of 316L stainless steel by applying the combination of surface treatments that consist of shot blasting followed by paste boronizing. Glass beads with diameter 250 microns and the blasting pressure of 6 bar has been used as the shot material in conducting shot blasting process. Paste boronizing process was conducted at temperature 950°C for 8 hours soaking. Data were collected and analyzed which concentrating on the samples’ microstructure, microhardness and wear evaluation. Shot blasting improves the case depth of boride layers formed after performing paste boronizing by boosting the boron diffusion owing to the grain refinement created by shot blasting. The ultimate combination of shot blasting and paste boronizing parameters enhance the case depth of the smooth and compact boride layers with high boron content. The hardness performance increase 624% compared to untreated 316L stainless steel which also highly improve the wear resistance of the material. In this investigation, these dual processes of surface treatment which are shot blasting and paste boronizing can be applied in fabricating the improved 316L stainless steel for industrial usages.
The implementation of boronizing in low alloy steel had been implemented tremendously in past years as this method offers excellent surface protection that led to enhancement of hardness and wear of the material. In conjunction to that, few parameters had been recognized as the factor that promotes boron diffusion into the surface of the material which is the selection of boronizing temperature and time. This study concentrated on the effect of pack boronizing on the boride layer thickness of 304 stainless steel which contained high amount of alloying elements. The microstructural analysis and boron layer thickness was measured and observed using optical microscopy and SEM analyzer. The microhardness of the material was measured using Vickers microhardness tester. The results portrayed that boronizing successfully induced boronizing layer containing FeB and Fe 2 B phases with thickness of 15μm. This resulted in major improvement of the microhardness values with improvement of 5 times compared to non-boronized samples.
This research is focused on three different heat treatments and they are austempering, tempering and a new heat treatment cycle of ductile iron and niobium alloyed ductile iron. The selection of all heat treatment parameters were based on TTT and CCT diagram which were simulated by JMart Pro Software. The microstructures were observed after etching with 2% Nital using light microscopy and Scanning Electron Microscope (SEM). The structures were verified by XRD analyses.
This study presents the effect of hardness and impact of 2.0% vanadium ductile iron after double quenching heat treatment method on different temperature. Addition of 2.0% Vanadium to ductile iron was produced through conventional CO2 sand casting method. The specimens were preheated to 500°C for 30 minutes, then oil quenched and austenitized at 900°C for 60 minutes before oil quenched again. After that, the specimens were tempered for 90 minutes at three different temperatures including (i) 500°C, (ii) 600°C, and (iii) 700°C respectively before cooled to room temperature by nature air. It is evident found that the addition of 2% Vanadium contributed to the slightly improved to the tensile strength properties but better hardness and impact compared to conventional ductile iron. The higher hardness and impact were found at 500°C and 600°C tempering temperature respectively.
This study focused on tensile strength properties inclusive of ultimate tensile strength and elongation values of niobium alloyed ductile iron in as cast and austempered conditions. The tensile specimens were machined according to TS 138 EN 10002-1 standard. Austempering heat treatment was conducted by first undergoing austenitizing process at 900°C before rapidly quenched in salt bath furnace and held at 350°C for 1 hour, 2 hours and 3 hours subsequently. The findings indicated that austempering the samples for 1 hour had resulted in improvement of almost twice of the tensile strength in niobium alloyed ductile iron. Improvement of elongations values were also noted after 1 hour austempering times. Increasing the austempering holding times to 2 hour and 3 hours had resulted in decrement in both tensile strength and elongations values.
The effects of mechanical properties and slurry erosive wear behaviour on combination of Chromium and Nickel Alloyed Ductile Iron before and after austempering process were investigated in this study. Specimens of pure ductile iron and addition of 0.16 % Cr+ 1.3 2% Ni alloyed ductile iron were produced through conventional CO2 sand casting method. The specimens were then austenitized at 900 0C before being tempered at 300 0C for 40 minutes. The slurry erosion of newly developed material were obtained by means of slurry erosive wear and the mechanical testing involved tensile test (TS 138 EN1002-1), Vickers hardness test and Charpy Impact test (ASTM E23). Roughness tests as well as SEM observations were also done to Cr-Ni alloyed ductile iron samples. All the testing was done to both as cast and austempered specimens. Austempering process heat treatment of Cr-Ni alloyed ductile iron has shown an increase in slurry wear and mechanical properties compared to as cast due to solid strengthening effect of Chromium and Nickel. Meanwhile, the austempering process does improve the hardness of alloyed ductile iron.
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