Experimental Study on Effect of Reflector Bed Designs Heated by Direct Solar Radiation for Hot Water Storage System

The aim of this research is to investigate the performance of different reflector bed design heated by direct solar radiation for a water storage system that can be used in accordance with the climate of Malaysia country. In general, this research is related to thermal efficient water heating system, specifically to improve the water heating system that exists nowadays. The focus is to improve the thermal efficiency by adding different absorber bed designs. Based on experimental results shown the temperature of the water increases more efficient and faster by using the curve reflector bed

The Effect of Surface Finish by Varying Machining Strategies of Five-Axis Flank Milling for Curvy Angled Convex Profile

The main aim of this research is to identify the best machining strategy on the five-axis flank machining curvy angled shapes using various machining approaches or strategies offered by CATIA V5 software. In machining of curvy angled shapes, the most important factor is to obtain the exact shape or machined part in certain acceptable tolerance with good surface finish. Hence, applying the right and the best machining strategy in Computer Aided Manufacturing (CAM) process is the most vital phase. The machining strategies that have been applied were Tanto Fan, Combin Tanto and Combin Parelm. In this study, only convex shape is analyzed throughout the study. Each of every machining part has been gone through a thorough analysis of surface finish by using Mitotuyo Surf-tester to determine the effect of the surface finish. Meanwhile, the parts chosen to be machined was modified aero-structural component part using the same aerospace standard material, Aluminum A6063. Based on the analysis carried out, the best machining strategy for the sample chosen part was Combin Parelm according to the mean Ra values. Factors contributed to the results obtained are further discussed in this paper

EXPERIMENTAL INVESTIGATION OF DRILLING PROCESS USING NANOFLUID AS COOLANT

Nanofluid coolant is one of the new formulation of cutting fluids used in machining in order to obtain better surface finish of products. In this study, the effect of various coolants (nanofluid and pure deionized water) and cutting parameters (cutting speed and feed rate) to the machining performances of titanium alloy was investigated by using drilling process. A series of experiments were conducted using Design of Experiment (DOE) and the machining performances were measured in terms of surface roughness and cutting temperature. The results show that better surface finish and lower cutting temperature can be obtained by using carbon nanofiber nanofluid compared to that of pure deionized water. The significant factors that influence the surface roughness of titanium alloy are feed rate and coolant. Coolant also plays an important role to reduce the cutting temperature during the drilling process

Unstable Temperature Distribution in Friction Stir Welding

In the friction stir welding process, a nonuniform and high generated temperature is undesirable. Unstable temperature and distribution affect thermal and residual stresses along the welding line, thus necessitating mitigation. This paper presents a simple method to prevent significant temperature difference along the welding line and also to help nullifying some defect types associated with this welding, such as end-hole, initial unwelded line, and deformed areas. In the experimental investigation, a heat and force thermocouple and dynamometer were utilized while couple-field thermomechanical models were used to evaluate temperature and its distribution, plastic strain, and material displacement. The suggested method generated uniform temperature distributions. Measurement results are discussed, showing a good correlation with predictions

A Study on Surface Roughness During Fused Deposition Modelling: A Review

Rapid Prototyping (RP) is technology used to produce a physical model or prototype directly from three-dimensional Computer-Aided-Design (3D CAD) data in a very short time. Fused Deposition Modelling (FDM) is a process for developing RP objects from plastic material by laying tracks of semi molten plastic filament on to a platform in precise layers from bottom to top. RP has been extensively used by manufacturers from different backgrounds to accelerate their product development and cycle time without neglecting product quality. In the RP process, surface finish is an important criterion as it can influence the part precision, post-handling expenses and functionality of the part. This paper presents a review of current studies on surface roughness using FDM. This paper also highlights design of experiments (DOE) and its association with surface finish

Effects of Cutter Geometrical Features on Machining Polyetheretherketones (PEEK) Engineering Plastic

When polyetheretherketone is used in structural applications it generally undergoes additional machining operations in order to form components. Machining PEEK can be a challenging task for manufacturers, however, especially when using a conventional cutting tool. This paper deals with the influence of a cutter’s geometrical features when machining polyetheretherketones engineering plastic on their machining performances. Three categories of end mills were designed and fabricated with varying rake angles, clearance angles and helix angles to investigate effects on machining surface roughness and burr formation. From the investigations conducted, it is evident that end mill geometrical features (rake angle, clearance angle and helix angle) have significant effects on machining surface roughness and burr formation. Increasing the rake angle and helix angle value will improved the machining surface roughness, however, in the case of varying clearance angles, there are no significant results for the surface roughness produced. It could be observed, however, that a 12° clearance angle produced better surface roughness compared to other angles. The findings from the deliberately conducted experiments can be used for the development of high performance cutting tools, especially for machining polyetheretherketones engineering plastic material

Parametric Study on Parameter Effects in Hybrid Micro Wire Electrical Discharge Turning

In this paper, a comprehensive parametric study on the effects of operating parameters in wire electrical discharge turning (WEDT) process was conducted. Total of eleven operating parameters were considered against the machined surface quality. The research focuses on the micro-turning of Ti6Al4V materials using Taguchi’s L12 orthogonal array at two level experimental designs. Analysis of variance (ANOVA) and signal-to-noise (S/N) ratio were used as statistical tools to evaluate the significances of the parameters. It was found that among the eleven operating parameters, only four parameters dominated and have statistical significant effects on the surface roughness values as discovered by ANOVA. The operating parameters were the rotational spindle speed (28.34%) as the most dominating factor, followed by intensity of pulse (24.18%), wire tension (20.57%) and stabilizer E (11.97%)

EFFECT OF PARAMETER CONDITION ON SURFACE ROUGHNESS FOR MACHINING AISI D2 HARDENED TOOL STEEL

Hardened steel such as AISI D2 is often used in mould and die industry. Some of the application required to have good surface quality profile and sophisticated free-form shape simultaneously. In current industry practice, manual polishing and grinding is often performed to achieve the required machining tolerance which tends to lower the productivity and difficulty in ensuring the component accuracy. Machining surface roughness is directly affected by the milling parameter and should be methodically analyzed. Thus, this paper aims to study the effect of milling parameter on surface roughness of AISI D2 tool steel. Response Surface Methodology (RSM) technique was used to evaluate the influence of milling parameter namely cutting speed, feed rate and depth of cut on machined surface. From the conducted study, based on the statistical analysis result it is found that feed rate is the main factor that influence the surface roughness followed by milling speed and depth of cut. In addition, the machined surface roughness observed was between 1.5 to 4.5 μm Ra

Optimization of Drill Geometry Design to Minimize Thermal Necrosis in Surgical Bone Drilling

During the orthopedic bone drilling surgery procedures, the friction between the drill and bones surface leads to a localized temperature increase results in thermal necrosis on the soft tissue surrounding the hole. The magnitudes of the friction energy are greatly dependent with the drill geometry design. Recognizing the importance on studying this phenomenon, this paper aim to investigate the effects of drill geometry on temperatures during the bone drilling procedure. Totals of 17 drills were design and tested with different geometry namely point angle, helix angle and web thickness on different penetration angle (0⁰, 15⁰, and 30⁰) to mimic the manually control penetration by the surgeon. From the conducted investigation, the most significant parameter that affects the temperature rise was the penetration angle followed by the point angle. In addition, the interaction between helix angle and web thickness also controlled the drilling temperature. From the result, the optimum drill-bit design geometry was 21.8% web thickness, 126.92° point angle and 36.53° helix angle which produces the minimum drilling temperature

HELICAL MICRO-HOLE DRILLING OF CHEMICALLY STRENGTHENED GLASS USING CAPSULE-SHAPED ELECTROPLATED DIAMOND TOOL

This study investigates the micro-hole drilling performance of chemically strengthened glass plate by using a capsule-shaped electroplated diamond tool and the helical drilling method. Three different helical pitch conditions were tested to drill holes with a diameter of 1 mm. The number of drilled holes, grinding force, and maximum crack size were measured along with the observation of the drilled holes to evaluate the performance of the micro-hole drilling. From the experimental results, it was found that as the size of helical pitch decreased, the number of drilled holes increases where the average grinding force generated becomes smaller. By using small helical pitch condition, 43 holes could be drilled but the maximum crack size generated at the outlet side of the drilled hole is not able to achieve the high-grade quality compared to the inlet side. The resultant grinding force generated when the tool tip nearing the outlet side of the glass plate has caused the large crack at a certain position on the outlet side