scholarly journals Thermo-Mechanical and Delamination Properties in Drilling GFRP Composites by Various Drill Angles

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1884
Author(s):  
Usama A. Khashaba ◽  
Mohamed S. Abd-Elwahed ◽  
Mohamed A. Eltaher ◽  
Ismail Najjar ◽  
Ammar Melaibari ◽  
...  
Keyword(s):  
Thrust Force ◽  
Infrared Camera ◽  
Heat Affect Zone ◽  
Measured Temperature ◽  
Machining Parameters ◽  
Cnc Machine ◽  
Dry Cutting ◽  
Specimen Holder ◽  
Drill Point ◽  
Speed Effect

This manuscript aims to study the effects of drilling factors on the thermal-mechanical properties and delamination experimentally during the drilling of glass fiber reinforced polymer (GFRP). Drilling studies were carried out using a CNC machine under dry cutting conditions by 6 mm diameter with different point angles of ∅ = 100°, 118°, and 140°. The drill spindle speed (400, 800, 1600 rpm), feed (0.025, 0.05, 0.1, 0.2 mm/r), and sample thickness (2.6, 5.3, and 7.7 mm) are considered in the analysis. Heat affected zone (HAZ) generated by drilling was measured using a thermal infrared camera and two K-thermocouples installed in the internal coolant holes of the drill. Therefore, two setups were used; the first is with a rotating drill and fixed specimen holder, and the second is with a rotating holder and fixed drill bit. To measure thrust force/torque through drilling, the Kistler dynamometer model 9272 was utilized. Pull-in and push-out delamination were evaluated based on the image analyzed by an AutoCAD technique. The regression models and multivariable regression analysis were developed to find relations between the drilling factors and responses. The results illustrate the significant relations between drilling factors and drilling responses such as thrust force, delamination, and heat affect zone. It was observed that the thrust force is more inspired by feed; however, the speed effect is more trivial and marginal on the thrust force. All machining parameters have a significant effect on the measured temperature, and the largest contribution is of the laminate thickness (33.14%), followed by speed and feed (29.00% and 15.10%, respectively), ended by the lowest contribution of the drill point angle (11.85%).

Experimental and Numerical Analysis of the Friction Drilling Process

2006 ◽  
Vol 128 (3) ◽  
pp. 802-810 ◽  
Author(s):  
Scott F. Miller ◽  
Rui Li ◽  
Hsin Wang ◽  
Albert J. Shih
Keyword(s):  
Thrust Force ◽  
Infrared Camera ◽  
Element Model ◽  
Single Step ◽  
Threshold Temperature ◽  
Force Model ◽  
Drilling Process ◽  
Measured Temperature ◽  
Friction Drilling ◽  
Hole Making

Friction drilling is a nontraditional hole-making process. A rotating conical tool is applied to penetrate a hole and create a bushing in a single step without generating chips. Friction drilling relies on the heat generated from the frictional force between the tool and sheet metal workpiece to soften, penetrate, and deform the work-material into a bushing shape. The mechanical and thermal aspects of friction drilling are studied in this research. Under the constant tool feed rate, the experimentally measured thrust force and torque were analyzed. An infrared camera is applied to measure the temperature of the tool and workpiece. Two models are developed for friction drilling. One is the thermal finite element model to predict the distance of tool travel before the workpiece reaches the 250°C threshold temperature that is detectable by an infrared camera. Another is a force model to predict the thrust force and torque in friction drilling based on the measured temperature, material properties, and estimated area of contact. The results of this study are used to identify research needs and build the foundation for future friction drilling process optimization.

Comparative Analysis between Conventional and Dry Turning

2017 ◽  
Vol 261 ◽  
pp. 267-274
Author(s):  
Pantelis N. Botsaris ◽  
Chaido Kyritsi ◽  
Dimitris Iliadis
Keyword(s):  
Experimental Data ◽  
Surface Roughness ◽  
Cutting Tool ◽  
Spindle Motor ◽  
Air Cooling ◽  
Machining Parameters ◽  
Turning Process ◽  
Dry Cutting ◽  
Cold Air ◽  
Cooling And Lubrication

In this paper, there is an attempt to monitor and evaluate machining parameters when turning 34CrNiMo6 material under different cooling and lubrication conditions. The machining parameters concerned are temperature of the cutting tool and the workpiece, level of vibrations of the cutting tool, surface roughness of the workpiece, noise levels of the turning process and current drawn by the main spindle motor. Four different experimental machining scenarios were completed, specifically: conventional wet turning process, dry cutting and two additional modes employing cooling by cold air. Experimental data were acquired and recorded by an optimally designed network of sensors. Experimental data were statistically analyzed in order to reach conclusions. According to the research that has been done, although, overall, minimum cutting tool and workpiece temperatures were observed under wet machining, cold air cooling is capable of achieving comparable cooling results to wet machining. The lowest values of surface roughness were achieved by wet machining, whereas the lowest level of cutting tool vibrations were observed under cold air cooling.

Effects of Twist Drill Point Angle on Thrust Force and Delamination Factor in Hybrid Fiber Composites Drilling

2014 ◽  
Vol 564 ◽  
pp. 501-506 ◽  
Author(s):  
Mohd Azuwan Maoinser ◽  
Faiz Ahmad ◽  
Safian Shariff ◽  
Tze Keong Woo
Keyword(s):  
Feed Rate ◽  
Thrust Force ◽  
Polymeric Composite ◽  
Drilling Process ◽  
Twist Drill ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Frp Composites ◽  
Delamination Factor ◽  
Drill Point

Drill point angle of twist drill has a significant effect on thrust force and delamination factor on drilled holes in fiber reinforced polymer (FRP) composites. In this study, three drill point angle of twist drill; 85°, 118° and 135° were used to drill holes in hybrid fiber reinforced polymeric composite (HFRP). HFRP composites were fabricated using vacuum infusion molding (VIM) technique. The test samples were cured at 90°C for two hours. In drilling process various drill point angle and feed rate were employed to investigate the effect of both parameters on thrust force and delamination factor when drilling the HFRP composite. The results showed that small drill point angle and low feed rate can reduce the thrust force leading to the reduction of damage factor at the holes entrance and exit.

Influence of Machining Parameters of the Drilling Polymers UHMW-PE and PTFE

2015 ◽  
Vol 1120-1121 ◽  
pp. 1297-1301 ◽  
Author(s):  
Breno Ferreira Lizardo ◽  
Luciano Machado Gomes Vieira ◽  
Juan Carlos Campos Rubio ◽  
Marcelo Araújo Câmara
Keyword(s):  
Thrust Force ◽  
Polymeric Materials ◽  
Machining Parameters ◽  
New Materials ◽  
Hole Quality ◽  
Tool Geometries ◽  
Dimensional Deviation ◽  
Fiber Metal ◽  
Ultra High Molecular Weight ◽  
Quality Surface

Over the years, with the increasing development of engineering materials, the emergence of new composites, fiber metal laminated, biomaterials, metal alloys etc., and with demand for products less expensive, less polluting and more efficient, the manufacturing engineering also needs to develop to be able to process these new materials. Materials and tool geometries, intelligent mechanisms, modular machines, also follow this setting. To that end, this work comes to raise the main parameters that influence in the hole quality surface of finished product. Were used two polymeric materials, ultra high molecular weight polyethylene (UHMW-PE) and polytetrafluoroethylene (PTFE), two feed rates, three rotations and three tool geometries, allowing to identify which of these parameters have greater influence on the thrust force and the characteristics of the finished product and dimensional deviation.

Effect of machining parameters on the surface finish of a metal matrix composite under dry cutting conditions

2015 ◽  
Vol 231 (6) ◽  
pp. 913-923 ◽  
Author(s):  
Brian Boswell ◽  
Mohammad Nazrul Islam ◽  
Ian J Davies ◽  
Alokesh Pramanik
Keyword(s):  
Surface Roughness ◽  
Metal Matrix Composite ◽  
Tool Life ◽  
Surface Finish ◽  
Feed Rate ◽  
Metal Matrix ◽  
Cutting Speed ◽  
Depth Of Cut ◽  
Machining Parameters ◽  
Dry Cutting

The machining of aerospace materials, such as metal matrix composites, introduces an additional challenge compared with traditional machining operations because of the presence of a reinforcement phase (e.g. ceramic particles or whiskers). This reinforcement phase decreases the thermal conductivity of the workpiece, thus, increasing the tool interface temperature and, consequently, reducing the tool life. Determining the optimum machining parameters is vital to maximising tool life and producing parts with the desired quality. By measuring the surface finish, the authors investigated the influence that the three major cutting parameters (cutting speed (50–150 m/min), feed rate (0.10–0.30 mm/rev) and depth of cut (1.0–2.0 mm)) have on tool life. End milling of a boron carbide particle-reinforced aluminium alloy was conducted under dry cutting conditions. The main result showed that contrary to the expectations for traditional machined alloys, the surface finish of the metal matrix composite examined in this work generally improved with increasing feed rate. The resulting surface roughness (arithmetic average) varied between 1.15 and 5.64 μm, with the minimum surface roughness achieved with the machining conditions of a cutting speed of 100 m/min, feed rate of 0.30 mm/rev and depth of cut of 1.0 mm. Another important result was the presence of surface microcracks in all specimens examined by electron microscopy irrespective of the machining condition or surface roughness.

Monitoring of hole surface integrity in drilling of bi-directional woven carbon fiber reinforced plastic composites

2020 ◽  
Vol 234 (12) ◽  
pp. 2432-2458 ◽  
Author(s):  
Tarakeswar Barik ◽  
Kamal Pal ◽  
Smruti Parimita ◽  
Priyabrata Sahoo ◽  
Karali Patra
Keyword(s):  
Carbon Fiber ◽  
Feed Rate ◽  
Thrust Force ◽  
Internal Surface ◽  
Carbon Fiber Reinforced Plastic ◽  
Fiber Reinforced ◽  
Fiber Reinforced Plastic ◽  
Reinforced Plastic ◽  
Circularity Error ◽  
Drill Point

Fiber-reinforced plastic is one of the top priorities lightweight materials with excellent mechanical properties for the aerospace industries in recent years. However, it is difficult to machine despite having unique properties due to its non-homogeneous and abrasive nature in alternate fiber and matrix layers. Thus, it is found to be a challenging task to drill hole on such hard-to-machine materials, which is highly essential for the development of most of the engineering structural components. The present work addresses various drilling-induced defects such as delamination, circularity error, and roughness variations in the hole surface during drilling of quasi-isotropic cross-fiber oriented bi-directional woven-type carbon fiber reinforced plastic laminate using a full factorial design of experiments for different drill geometry. The response surface methodology was considered for the regression model development, which was found to be highly significant. The machining forces with associated torque have also been acquired during drilling, which was divided and further analyzed in time domain to correlate with drilling flaws. The drilling-induced delamination was found to be higher at a high feed rate using a higher drill point angle due to substantial thrust force generation at the initial stages in the drilling cycle. However, the internal surface finish with associated circularity error was reduced for higher spindle speed with less feed rate using a low drill point angle because of low torque fluctuation at the final drilling phases. The axial thrust force was found to be a prime indicator of drilled hole surface delamination, whereas drilling torque precisely indicated internal surface roughness as well as circularity error. The global root mean square, along with a local peak of thrust and torque, both were highly essential to completely characterize the drilled hole quality.

scholarly journals Analysis of Surface Roughness and Flank Wear Using the Taguchi Method in Milling of NiTi Shape Memory Alloy with Uncoated Tools

Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1259
Author(s):  
Emre Altas ◽  
Hasan Gokkaya ◽  
Meltem Altin Karatas ◽  
Dervis Ozkan
Keyword(s):  
Surface Roughness ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Flank Wear ◽  
Cutting Tools ◽  
Dominant Factor ◽  
Niti Shape Memory Alloy ◽  
Machining Parameters ◽  
Nose Radius ◽  
Dry Cutting

The aim of this study was to optimize machining parameters to obtain the smallest average surface roughness (Ra) and flank wear (Vb) values as a result of the surface milling of a nickel-titanium (NiTi) shape memory alloy (SMA) with uncoated cutting tools with different nose radius (rε) under dry cutting conditions. Tungsten carbide cutting tools with different rε (0.4 mm and 0.8 mm) were used in milling operations. The milling process was performed as lateral/surface cutting at three different cutting speeds (Vc) (20, 35 and 50 m/min), feed rates (fz) (0.03, 0.07 and 0.14 mm/tooth) and a constant axial cutting depth (0.7 mm). The effects of machining parameters in milling experiments were investigated based on the Taguchi L18 (21 × 32) orthogonal sequence, and the data obtained were analyzed using the Minitab 17 software. To determine the effects of processing parameters on Ra and Vb, analysis of variance (ANOVA) was used. The analysis results reveal that the dominant factor affecting the Ra is the cutting tool rε, while the main factor affecting Vb is the fz. Since the predicted values and measured values are very close to each other, it can be said that optimization is correct according to the validation test results.

Multiresponse optimization of drillability factors and mechanical properties of chitosan-reinforced polypropylene composite

2020 ◽  
pp. 089270572093916
Author(s):  
Nafiz Yaşar ◽  
Mustafa Günay ◽  
Erol Kılık ◽  
Hüseyin Ünal
Keyword(s):  
Surface Roughness ◽  
Feed Rate ◽  
Thrust Force ◽  
Flexural Modulus ◽  
Cutting Speed ◽  
Industrial Applications ◽  
Uniaxial Tensile ◽  
Machining Parameters ◽  
Molding Method ◽  
Machining Conditions

In this study, the mechanical and machinability characteristics of chitosan (Cts)-filled polypropylene (PP) composites produced by injection molding method were analyzed. Uniaxial tensile, impact, hardness, and three-point flexural tests were used to observe the influence of Cts filler on the mechanical behavior of PP. For the machinability analysis of these materials, drilling experiments based on Taguchi’s L27 orthogonal array were performed using different drill qualities and machining parameters. Then, machining conditions are optimized through grey relational analysis methodology for machinability characteristics such as thrust force and surface roughness obtained from drilling tests. The results showed that tensile, flexural strength, and percentage elongation decreased while impact strength increased with adding the Cts filler to PP. Moreover, it was determined that the tensile and flexural modulus of elasticity increased significantly and there was a slight increase in hardness. Thrust forces decreased while surface roughness values increased when the Cts filler ratio and feed rate was increased. The optimal machining conditions for minimizing thrust force and surface roughness was obtained as PP/10 wt% Cts material, uncoated tungsten carbide drill, feed rate of 0.05 mm/rev, and cutting speed of 40 m/min. In this regard, PP composite reinforced by 10 wt% Cts is recommended for industrial applications in terms of both the mechanical and machinability characteristics.

The Research of Five-Axis NC High Efficient Machining Technology for UAV Integral Impeller

2014 ◽  
Vol 598 ◽  
pp. 189-193
Author(s):  
Hui Zhao ◽  
Yu Jun Cai ◽  
Guo He Li
Keyword(s):  
Process Analysis ◽  
Coordinate Measuring Machine ◽  
Machining Process ◽  
Machining Parameters ◽  
Program Optimization ◽  
Cnc Machine ◽  
Rough Machining ◽  
High Efficient ◽  
Measuring Machine ◽  
Five Axis

In this paper, a very detailed process analysis for UAV integral impeller was made. According to the specific processing requirements, the appropriate CNC machine, blank and cutting tools have been choosing. In the rough machining process, various machining strategies have been used for comparing and analyzing, finally a more efficient roughing method with the accurate machining parameters will be obtained. At the same time the machining method have been improved and the processing parameters also have been determined in the semi-finishing process. Through the simulation processing in VERICUT, the possibility of the existence of interference which is usually occurred in the actual processing can be ruled out and the program optimization will be finished in the meantime. Finally, using intelligent three-coordinate measuring machine the consequence will be verified and inspected in the actual machining process.

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