THE EFFECTS OF SILICA SAND (Si02) AND ZIRCONIA (Zr02) ON THE MECHANICAL AND THERMAL PROPERTIES OF THE PRESSURELESS SINTERED Al203-Si02-Zr02 COMPOSITE

The research work presents an investigation on the pressureless sintering, microstructure and mechanical properties of three component ceramic composite material consisting of alumina, silica and zirconia for structural applications. The effect of each component composition on the physical and mechanical properties was studied. Mechanical properties including fracture toughness, flexural strength, and hardness at ambient temperature were determined and thermal shock resistance properties up to 950°C were also investigated. These properties were compared among the monolithic A1203, Al203-Zr02 (AZ) and Al203-Si02-Zr02 (ASZ) composites. The microstructure of sintered, thermal shocked and fractured surface states was investigated using FESEM and AFM. A three phase microstructure was adopted with a composition of 70% by weight of alumina, 10% by weight of silica and 20% by weight of zirconia. The reinforcements of the Si02 and Zr02 contributed in improving the mechanical properties of the composite

THE EFFECTS OF SILICA SAND (Si02) AND ZIRCONIA (Zr02) ON THE MECHANICAL AND THERMAL PROPERTIES OF THE PRESSURELESS SINTERED Al203-Si02-Zr02 COMPOSITE

The research work presents an investigation on the pressureless sintering, microstructure and mechanical properties of three component ceramic composite material consisting of alumina, silica and zirconia for structural applications. The effect of each component composition on the physical and mechanical properties was studied. Mechanical properties including fracture toughness, flexural strength, and hardness at ambient temperature were determined and thermal shock resistance properties up to 950°C were also investigated. These properties were compared among the monolithic A1203, Al203-Zr02 (AZ) and Al203-Si02-Zr02 (ASZ) composites. The microstructure of sintered, thermal shocked and fractured surface states was investigated using FESEM and AFM. A three phase microstructure was adopted with a composition of 70% by weight of alumina, 10% by weight of silica and 20% by weight of zirconia. The reinforcements of the Si02 and Zr02 contributed in improving the mechanical properties of the composite

Investigation on the multiple plies structure of aluminum-lithium alloy and glass fiber composite with respect to deformation failure

The deformation behavior and mechanical properties based on the aluminum-lithium alloys (FMLs) was investigated to optimize the manufacturing process and further interface interaction. The primary structures of the FML composites were made with two sets of plies. From there, six secondary composites with different fibre sheet orientations were made. Then, interlaminar tensile, flexural, and peeling properties of FMLs were tested. The fiber orientation role in the case of failure behaviors of FMLs under different conditions was also revealed. The results have indicated that the plies design significantly enhanced the interlaminar properties of the FMLs and orientation of fiber laying has significantly affected the flexural strength. The peeling test has shown higher fiber-to-metal interfacial bonding with the value of ≥80 N m−2 over metal-to-metal adhesion. The plies increase the mechanical properties of composite based at fiber orientation and thickness, but too much impairs performance. The 3/2 plies showed a value of ≤385 MPa, which has better results in axial structure analysis than over 4/2 composite layers. The peak values appeared under different parameters like adhesive bonding and parallel fiber orientation, represented in the qualitative analysis section. The surface microscopy of aluminum-lithium alloy sheet and cross-section failure morphology of composite has been done at a different sighting. Surface characterization, fiber orientation breakdown, and deformation morphology have been studied concerning alloys' elongated grains and micro pits

Effect Of Surface Topography Of 8090 Al-Li Alloy During Abrasive Waterjet Peening Process

Abrasive water jet (AWJ) peening strengthening test of aluminum-lithium alloy (8090Al–Li) was carried out with a variety of pressure process parameters. The research was done on the roughness as well as the morphology of the treated samples. A high dislocation density formed in the area of the workpiece that was subjected to the peening process. The result was a surface that was both rough and hardened. The abrasive effect took place in the area where the collapse took place. The fact that this method was the most effective option for treating the surface of the metal was very beneficial. According to the findings, the surface roughness, grain size, micro-strain, erosive effect, and micro-hardness of the alloy were all considerably affected by various peening settings. In this instance, the rise in pressure caused the surface roughness to increase as well. In addition, the microcrystalline structure was shown to have diminished in the treated area by the abrasive peening. The research demonstrated how the effect of varying the peening pressure can reduce the amount of surface roughness on materials. In comparison to the initial sample, the roughness reached its highest values of 62 μm to 92 μm and rose by 7.87 to 27.56 %. These results indicate a significant increase. In comparison, the average surface roughness of the equivalent area increased to 30.04 μm. According to the experimental observation, the AWJ peening collapse limits that were acquired by the proposed sample surface and metallographic images were extremely complete and accurate

Prediction of abrasive waterjet machining of sheet metals using artificial neural network

High pressure waterjet technology has received a wider acceptance for various applications involving machining, cleaning, surface treatment and material cutting. Machining of soft and thin materials with acceptable cutting quality requires a relatively low waterjet pump capacity typically below 150 MPa. The present study attempts to predict the surface roughness during the waterjet machining process for a successful cutting of sheet metals using low pressure. Artificial neural network model was used as the method for prediction. Taguchi method with L36 orthogonal array was employed to develop the experimental design. A back-propagation algorithm used in the ANN model has successfully predicted the surface roughness with the mean squared error to be below 10%. This summarizes that ANN model can sufficiently estimate surface roughness in the abrasive waterjet machining of sheet metals with a reasonable error range

Optimization of waterjet paint removal operation using artificial neural network

Paint removal of automotive parts without environmental effects has become a critical issue around the world. The high pressure waterjet technology has received a wider acceptance for various applications involving machining, cleaning, surface treatment and material cutting. It offers an advantage to remove the automotive paint due to its superior environmental benefits over mechanical cleaning methods. Therefore, it is important to predict the waterjet cleaning process for a successful application for the paint removal in the automotive industry. In the present work, ANN model was used to predict the surface roughnes after the paint removel process of automotive component using the waterjet cleaning operation. A response surface methodology approach was employed to develop the experimental design involving the first order model and the second order model of central composite design. Into training and testing, a back-propagation algorithm used in the ANN model has successfully predicted the surface roughness with an average of 80% accuracy and 3.02 mean square error. This summarizes that ANN model can sufficiently estimate surface roughness in waterjet paint removal process with a reasonable error range

Surface Roughness Analysis on Sheet Metals During AWJ Machining Using Low Pressure

The present study discusses the effect of abrasive waterjet machining (AWJ) parameters on surface roughness during cutting of sheets metals of stainless steel 304 and pure copper. A relatively low hydraulic pressure below 150 MPa was used. Several machining parameters were chosen namely pressure, traverse rate, stand-off distance and abrasive mass flowrate. It was found that increasing the pressure leads to an increase in the surface roughness. Varying other parameters did not clearly show any trends on the surface roughness. A higher surface roughness happened during AWJ machining of stainless steel 304 compared to pure copper due to its former higher hardness. The surface roughness at the upper region closer to the top surface is higher than the bottom section regardless of machining parameters. Furthermore, embedded particles are more dominant in pure copper than stainless steels 304. It can be concluded that a low water pressure in AWJ machining process can be used to cut sheet metals successfully with acceptable cutting quality

A review on peening processes and its effect on surfaces

Surface treatment methods are widely used in various industries to improve the material performance and change their physical properties. The methods can be categorised according to the nature of the operation as mechanical, chemical, electrochemical and case hardening processes. Mechanical surface treatment methods are mainly utilised to add compressive residual stresses in surface layers thus usually improving the life of engineering components. Among various mechanical surface treatment methods, peening process is common in treatment nature by treating the surface using mechanical means. Three peening processes, namely shot peening (SP), laser shock peening (LSP) and waterjet peening (WJP) are selected to be the focus of the present paper due to their similarity based on impulsive effect to the surface by the input force through unguided tools in repetitive irregular manner without any oscillating or vibrating movement of tools. A comprehensive review is presented to discuss each of the peening processes and their effects on the surface integrity in terms of the topography, mechanical properties and microstructural changes. The investigation includes the discussion on the existing advantages, disadvantages and technological barriers of peening technologies for industrial applications. Detailed examples of recent advances in the peening methods are also discussed. The results show that the SP method produces more roughness as compared to LSP and WJP methods. However, fatigue strength is better without considerable changes in roughness and corrosion after LSP and WJP treatments. It can be concluded that the peening processes can improve the material performance with acceptable qualities for in-service application in industries

Investigation on welding distortion in stainless steel sheet using gas tungsten arc welding process

TIG welding has found wide applications in various industries for sheet metal joining process due to its simple process with high quality welds. However, it still experiences various form of defects to the weld components such as incomplete fusion, undercut, cracks and distortion which might affect production accuracy, appearance and strength of weld components. It is obvious that various welding parameters can affect the welding distortion. The present study attempts to investigate the effect of welding parameters namely welding current and diameter of filler rod on the distortion angle, tensile strength and change in microstructures. The experiment was performed on a closed butt joint type of welding using a commercial TIG welding machine. A full factorial experiment was utilized in the present study. A higher welding current produced more heat input into the weld zone thus resulting in a higher angular distortion. Similarly, a bigger diameter of filler rod produced more angular distortion attributed to the bigger size of weld bead. While, the tensile strength increased with an increase of welding current whereas, the filler rod diameters showed no clear and direct effect. Based on the microstructures of weld area, there were full penetration joints with no obvious defects such as hot cracking and porosities

Development of fiber metal laminate composite with different glass fiber gsm

The fiber metal laminates based on aluminum-lithium alloy (FMLs) and glass fiber sheets were investigated to improve the stiffness tolerance. The aluminum-lithium sheets were treated with different techniques for getting the desired thickness and strength. Then, FMLs 4/2 were prepared by the optimized process. The two different types of GSM (gram square meter) glass fiber sheets have been used for the development of FMLs, GSM of the sheet are 300 and 600. Floating roller and tensile strength tests were used to gauge the FMLs' mechanical qualities. The results showed that the T3 doping state was primarily responsible for strengthening the aluminum-lithium alloy. When compared to high GSM, however, FMLs showed a small gain in strength and a clear improvement in elastic modulus regardless of the fibres plies and sampling orientation. However, during various GSMs, FMLs show outstanding interlaminar characteristics despite their dissimilar densities. A new design of composite with a high GSM value was also confirmed to improve FMLs' tensile resistance. Microscopy and morphological analysis have been performed, and the findings provide insight into the rationale for the enhanced properties of fibre metal laminate composites. The epoxy-aluminum alloy sheet interface morphologies were then studied using SEM. In this investigation, apparent surface energy was found to have a major role in enhancing adhesive bonding at the fully wetted stage, while the value of roughness might significantly affect adhesion strength at the partially wetted condition