Comparative study of mechanical technologies over laser technology for drilling carbon fiber reinforced polymer materials

19-32More researchers have been worked to increase the quality of the machined composite materials. In this paper, a comparative experimental study of mechanical techniques over the laser techniques has been performed in the drilling process by using the carbon fiber reinforced polymer (CFRP). In order to identify the best process among the mechanical drilling (MD) and laser drilling (LD) technology various analysis methods like normality analysis, control chart analysis, and process capability analysis have been performed. Process capability index analysis for case study 1 and interval plot analysis for case study 2 have been employed to evaluate the best process comparatively. Experiments have been performed in a vertical machining center (VMC) and CO2 laser. The final results revealed that the MD process is the best technology for drilling CFRP. Therefore, this work has been important for small-scale industries

Studies on Testing and Modelling of Formability in Aluminium Alloy Sheet Forming

In this paper, the influence of tensile and formability parameters on the forming limit diagram is reported and a model is created to predict the forming limit strains of various grades of aluminium sheet metals. Aluminium alloys of grades AA5052, AA6061 and AA8011 with a thickness 0.8 mm, 1.0 mm and 1.2 mm have been selected for the study. Experiments are conducted to construct the forming limit diagram (FLD) for the above mentioned sheet metals. Tensile tests were conducted to evaluate strain hardening index, strength coefficient, ductility, yield strength, ultimate tensile strength, normal anisotropy, planar anisotropy and strain rate sensitivity. The fractured surfaces of the specimens were viewed with a scanning electron microscope. Using Design of Experiments (DOE), regression modelling was done by taking the tensile properties and formability parameters as input variables and the forming limit strain as response. Regression equations were created to predict the limiting strain values at the tension-tension, plane strain and tension-compression strain states. The experimentally evaluated strain values were compared with the predicted strain values and the comparison shows good agreement of the values. The Taguchi method of optimization was used to find the optimum values for the input variables and using these optimum values, the optimum forming limit strains were found. It is found that the so created regression model predicts the FLD of various grades of sheet metals by which the tedious job of experimental determination of the FLD can be avoided

Optimization of multipoint incremental sheet metal forming of SS430 sheets using GRA

326-333Incremental sheet metal forming (ISF) is one of the best flexible manufacturing processes used to convert a sheet metal into required final shape using tool movement. In incremental sheet metal forming process, a single pointed forming tool is allowed to move over the sheet metal as per the pre-programmed numerical control of a computer. The advantage of making any complex part without die confirms its importance in the emerging automated industries. But this process has some limitations such as less formability and high surface roughness compared to the conventional forming process. Longer processing time is another drawback of the incremental sheet forming. This paper proposes a newly designed multi-point incremental forming (MPIF) tool to avoid the drawbacks faced by industry in increasing the formability and wall angle of the sheet metal with reduced time. The sheet metal stainless steel (SS) grade 430 has been used for forming process and the outputs obtained from MPIF and single point incremental forming (SPIF) have been compared with respect to wall angle, formability, surface roughness, spring back and forming time. Grey relational analysis (GRA) has been used to find the optimal value for the various responses obtained. The analysis of variance (ANOVA) calculation method has also been used to find the factors that influence the output responses. The responses obtained by the experiment have proved that the multipoint tool results better output

Comparative study of mechanical technologies over laser technology for drilling carbon fiber reinforced polymer materials

More researchers have been worked to increase the quality of the machined composite materials. In this paper, acomparative experimental study of mechanical techniques over the laser techniques has been performed in the drillingprocess by using the carbon fiber reinforced polymer (CFRP). In order to identify the best process among the mechanicaldrilling (MD) and laser drilling (LD) technology various analysis methods like normality analysis, control chart analysis,and process capability analysis have been performed. Process capability index analysis for case study 1 and interval plotanalysis for case study 2 have been employed to evaluate the best process comparatively. Experiments have been performedin a vertical machining center (VMC) and CO2 laser. The final results revealed that the MD process is the best technologyfor drilling CFRP. Therefore, this work has been important for small-scale industries