NOVEL METHOD OF USING CHILLED AIR MACHINING ON UNIDIRECTIONAL CARBON FIBER REINFORCED PLASTIC FOR LONG TERM USAGE OF SOLID CARBIDE CUTTING TOOL

Carbon fiber reinforced plastic (CFRP) is an expensive composite which has become valuable material as the demand for this composite increased in the industries. It is suitable to be used in automotive, aerospace and aircraft because of its properties which is stronger than steel and also stiffer than titanium while retaining its lighter weight. Fabrication of CFRP is through molding process but machining processes such as milling is needed especially during the component assembling stage. Even though, the development of fiber-reinforced plastic composites has led to advantages over metal, however, there are still some issues concerning the machinist. These include excessive tool wear and poor surface quality due to delamination and fiber pull-out during machining. Because there are at least two phases of materials in FRP, each with unique mechanical properties, the material removal mechanism is different from that observed when machining homogeneous materials, such as metals. To overcome these problems, polycrystalline diamond (PCD) is commonly used to machine FRP. However, it is costly as it takes longer to produce smoother surfaces compared to other cutting tools. Therefore, carbide cutting tools which are one of the hardest materials and cheaper compared to PCD, have been considered and often used in industry to machine CFRP. Although carbide cutting tools have the potential but its machining performance not as good as PCD’s. Chilled air is a near dry method which is not only environmentally friendly as it produces no chemical pollution, but it can also decrease tool wear and improve the surface quality. In this study, for chilled air machining, the cooled air will be applied to the cutting tool by using vortex tube. By hypothesis, by cooling down the heat generated during machining which is the main cause of tool wear and surface quality to occur, the production cost of CFRP can be reduced as well compared to dry machining

Study on tool wear during milling CFRP under dry and chilled air machining

Carbon fibre reinforced plastic (CFRP) is an expensive composite that, as industry demand for this composite has increased, has become a valuable material. CFRP is suitable to be used in automotive, aerospace and aircraft industries, because of its properties, which are being stronger than steel and stiffer than titanium, while retaining its lighter weight. This paper presents the tool wear on solid carbide cutting tool during milling CFRP under dry and chilled air cutting conditions. The experiments were designed by using Central Composite Design (CCD) with range of 160- 200 m/min (cutting speeds), 0.125- 0.25 mm/tooth (feed rate) and 0.5- 1.0 mm (depth of cut). In this study, air pressure of 0.55 MPa and chilled air (with a temperature of -10 Celsius and a flow velocity of 4.10 m/s) were applied to the cutting tool using a vortex tube. The longest tool lives of 7.22 minutes (dry machining) and 7.33 minutes (chilled air machining) were achieved at the lowest feed rate of 0.125 mm/tooth, a cutting speed of 179 m/min, and depth of cut of 0.71 mm. The polished/shined surface of the tool wear area, which was caused by the abrasive nature of carbon and the sliding mechanism of chips during machining, shows the presence of abrasion wear. Less tool wear was observed under chilled air machining conditions than dry machining. Based on the developed mathematical model, feed rate was identified as the primary significant item that influenced tool life. In conclusion, the application of chilled air during CFRP machining helped to improve the tool life of uncoated carbide cutting tools compare to dry machining

Thermal modelling and analysis of batik canting design

Canting or ‘tjanting’ is a traditional hand tool that is used to apply wax in lines and fine dots on a cloth to create beautiful batik designs. In this study, the thermal and structural characteristics of the wax determined via differential scanning calorimetry (DSC) and fourier transform infrared (FTIR) spectroscopy respectively. The actual temperature distribution in the current batik canting was determined using laser thermometer. The model of the canting was then simulated via Solidworks 2013 to obtain the heat distributed along the length of the canting body. The thermal simulation of the canting model revealed that the maximum and minimum temperature were 72.3°C and 32.0°C respectively. The temperature readings obtained were found to be consistent with the actual heat distribution results for the canting with maximum temperature discrepancy between 3-6%. It is envisioned that with more ergonomic and ease of use of the batik tool will enhance the batik making process and industry in Malaysia

Analysis of defects on machined surfaces of aluminum alloy (Al 7075) using imaging and topographical techniques

Aluminum alloys 7075 (Al 7075) are widely used for various industrial components in which machining operations are often conducted during their manufacturing process. However, the machining operations could introduce defects on the machined surfaces of the components which will be carried over and may lead to either issues in the subsequent fabrication process or failure during the products' service life. This study investigates the machined surface's defects of Al 7075 underwent drilling operations using imaging and topographical techniques which include optical microscope, scanning electron microscope and 3D surface profiler. Surface roughness was analysed with respect to the surface defects to investigate the correlation between the roughness parameters and topographical features of the machined surfaces. The defects found on the machined surfaces of Al 7075 are microcrack, adhesion, feed mark and burr. Surface roughness was found to be highly influenced by topographical features particularly feed mark. Thus, in addition to measuring the roughness, inspection through imaging and 3D topographic techniques is important for analyzing the surface characteristic in order to determine the defects, hence deducing the detailed surface features and deformation caused by the drilling operations

Study on drilling induced delamination of woven kenaf fiber reinforced epoxy composite using carbide drills

In this research study, it presents the influences of drilling parameters on the delamination factor during the drilling of woven kenaf fiber reinforced epoxy composite laminates when using the carbide drill bits. The purpose of this study is to investigate the influence of drilling parameters such as cutting speed, feed rate and drill sizes on the delamination produced when drilling woven kenaf reinforced epoxy composite using the non-coated carbide drill bits. The damage generated on the woven kenaf reinforced epoxy composite laminates were observed both at the entrance and exit surface during the drilling operation. The experiments were conducted according to the Box Behnken experimental designs. The results indicated that the drill diameter has a significant influence on the delamination when drilling the woven kenaf fiber reinforced epoxy composites

Optimization of machining parameters during milling of carbon fibre reinforced plastics

This paper investigates the optimization of cutting parameters on tool life of carbide cutting tools during milling Carbon Fibre Reinforced Plastic (CFRP) of unidirectional fiber orientation of 90°. CFRP is one form of composite material which is highly demand by manufacturing sectors due to its light weight ratio and stronger than aluminium properties. Despite of having high demand in industry, researchers face a lot of problems during machining CFRP during assemble phase. High tool wear and short tool life of cutting tool used during machining, lead to high production cost are among the factors which concern the machinist the most. This research is carried out by using spindle speed of 1000 rpm to 8700 rpm, feed rate of 500 mm/min to 1000 mm/min and depth of cut of 1 mm to 1.5 mm which will be acted as the input variable. The output response is in form of tool wear and tool life of carbide cutting tool. In this study, CNC Mazak Milling Machine with maximum spindle speed of 12000 rpm is used to mill CFRP. Box Behnken Design under Response Surface Methodology is used as Design of Experiment to generate 15 runs. The optimization of cutting parameters for 90° is analyzed using Analysis of Variance (ANOVA). It was found that, higher spindle speed, lower feed rate and lower depth of cut lead to lowest tool wear and highest tool life. ANOVA analysis recorded that feed rate is the most significant factor that influence tool life

The optimization study on the tool wear of carbide cutting tool during milling Carbon Fibre Reinforced (CFRP) using Response Surface Methodology (RSM)

Carbon Fibre Reinforced Plastic (CFRP) composite has become one of famous materials in industry, such as automotive, aeronautics, aerospace and aircraft. CFRP is attractive due to its properties, which promising better strength and high specification of mechanical properties other than its high resistance to corrosion. Other than being abrasive material due to the carbon nature, CFRP is an anisotropic material, which the knowledge of machining metal and steel cannot be applied during machining CFRP. The improper technique and parameters used to machine CFRP may result in high tool wear. This paper is to study the tool wear of 8 mm diameter carbide cutting tool during milling CFRP. To predict the suitable cutting parameters within range of 3500-6220 (rev/min), 200-245 (mm/min), and 0.4-1.8 (mm) for cutting speed, speed, feed rate and depth of cut respectively, which produce optimized result (less tool wear), Response Surface Methodology (RSM) has been used. Based on the developed mathematical model, feed rate was identified as the primary significant item that influenced tool wear. The optimized cutting parameters are cutting speed, feed and depth of cut of 3500 rev/min, 200 mm/min and 0.5 mm, respectively, with tool wear of 0.0267 mm. It is also can be observed that as the cutting speed and feed rate increased the tool wear is increasi

Optimization of milling carbon fibre reinforced plastic under chilled air machining

Carbon fibre reinforced plastic (CFRP) is an expensive composite that, as industry demand for this composite has increased, has become a valuable material. CFRP is suitable to be used in automotive, aerospace and aircraft industries, because of its properties, which are being stronger than steel and stiffer than titanium, while retaining its lighter weight. This paper presents the optimization of cutting parameters during milling CFRP under chilled air machining. A Central Composite Design (CCD) of the Response Surface Method (RSM) has been used to design the experimental runs and to develop a mathematical model based on the data collected. The experiments were arranged using various cutting parameters of cutting speed (160- 200 m/min), feed rate (0.125-0.375 mm/tooth), and depth of cut (0.5-1.0 mm). In this study, air pressure of 0.55 MPa and chilled air (with a temperature of -10 degrees and a flow velocity of 4.10 m/s) were applied to the cutting tool using a vortex tube. It have been observed that the optimized cutting parameters were cutting speed, feed and depth of cut of 194 m/min, 0.5 mm/tooth and 0.5 mm, respectively, with tool life, surface roughness and delamination factor at 9.287 minutes, 1.585 μm and 1.086, respectively

Tool wear during milling laminated carbon fibre reinforced plastic

Carbon fibre reinforced plastic (CFRP) is a composite which has the best strength to weight ratio among the construction materials. It becomes valuable as the demand for this composite has increased dramatically especially in automobile and aerospace industry. Cutting speed of 160–194 m/min and a feed rate of 0.14–0.225 mm/tooth on solid uncoated carbide during the milling process were discussed. It is observed that the wear area is found polished and shining which is due to the abrasive nature of the carbon. The wear region is found high at higher cutting speeds and feed rates. The reduction of tool life is 40%, 30% and 14% as the cutting speed, feed rate increase and depth of cut increased respectively

Optimization of milling carbon fiber reinforced plastic using RSM

Carbon Fibre Reinforced Plastic (CFRP) is extensively used nowadays especially in the industries due to its desirable properties of high strength, light weight and high resistance to corrosion. However, the machining of CFRP composites requires great specification and requirement as it is difficult to be machine. Besides, improper technique and parameters used to machine CFRP may result in poor surface quality such as high surface roughness and delamination. This study was done on a CFRP panel with solid uncoated carbide tool with diameter of 8 mm was used as cutting tool. Thus, this project investigates the influence of the cutting parameters which are spindle speed, feed rate and depth of cut to the surface quality of the CFRP by undergoing milling operation. The cutting parameters used during the milling operation of the CFRP panel ranged from 500 rpm to 3500 rpm for the cutting speed, feed rate from 100 mm/min to 900 mm/min and lastly 0.5 mm to 2.0 mm range for depth of cut. 15 runs of experiments is performed based on the Central Composite Design (CCD) of Response Surface Methodology. Through this study, the optimum cutting parameters during milling of CFRP is determined and the main factors affecting the surface quality are also highlighted. Based on the developed mathematical model, the feed rate was identified as the primary significant parameter that influenced surface roughness and delamination. In conclusion, the influence of the cutting parameters on the CFRP panel is higher cutting speed, lower feed rate and lower depth of cut resulted in low surface roughness and delamination factor. Feed rate was identified to be the primary significant cutting parameter that contributes to low surface roughness and delamination factor. The optimized cutting parameters were cutting speed, feed rate and depth of cut of 3061 rpm, 211.34 mm/min and 0.72 mm respectively with surface roughness of 1.34 um and delamination factor of 1.08