Percentage Contribution Of Process Parameters Research Articles

Microstructure, hardness, and wear properties of AA6061/WC nanocomposite fabricated by friction stir processing

Friction stir processing (FSP) is a solid-state microstructural modification technique that has recently become an effective tool to refine microstructures and improve the mechanical properties of metals. In the current study, optimization of FSP parameters, including tool rotational speed, transverse feed, number of passes, and tungsten carbide (WC) nanoparticle volume fractions on mechanical and wear properties of the fabricated AA6061/WC nanocomposite was studied. Optical microscopy and scanning electron microscopy are used for microstructural observations. The process parameters are optimized using the Taguchi technique for single responses towards microhardness and weight loss and the Desirability approach for both responses. The percentage contribution of process parameters is estimated using analysis of variance. The microstructure observation shows that the proper selection of FSP parameters leads to a homogeneous dispersion of the WC particles throughout the matrix, thereby producing a defect-free AA6061/WC nanocomposite without voids. Also, the severe plastic deformation and heat generation during FSP cause the breaking of coarse particles, WC particles, and porous holes and create an ultrafine grain-sized structure via dynamic recrystallization. The results indicated that the microhardness value of the processed composite was found to be 144 VHN, which is 39.81% higher than that of the base metal. Also, the weight loss of all samples decreased as compared to the base metal. Also, it can be observed that the number of passes is the most significant factor for microhardness, with a 40.1% contribution, and for minimum weight loss, the volume fraction is the most significant factor, with a 56.94% contribution. The optimum process parameter combination was found to be 1800 rpm rotation speed, 120 mm/min of transverse feed, 6% volume fraction, and 3 passes that resulted in obtaining optimum values for micro hardness and weight loss. The surface composite developed in this research is considered a suitable material for applications demanding lightweight and enhanced surface properties, including automotive, aerospace, marine, defense, and transportation industries.

Machining, Characterization and Optimization: A Novel Approach for Machining Channels on Silicon Wafer Using Tailor-Made Micro Abrasive Jet Machining

Literature reveals that machining a silicon wafer is very arduous due to its high brittle nature and low fracture toughness. Researchers have attempted to machine features on a silicon wafer using both conventional and non-conventional processes and both have their merits & demerits. Abrasive jet machining (AJM) is one of the efficient non-conventional machining methods for machining hard and brittle materials. Removal of material occurs by impact erosion and is free from Heat Affected Zone (HAZ) and resolidification. These advantages make AJM a potential process for machining silicon wafers. Therefore an attempt has been made to machine channels on silicon wafers using a Tailor-made AJM setup. The process parameters selected for machining channels on a silicon wafer are air pressure, Feed rate (FR), and Standoff distance (SOD). The output responses considered for characterization are material removal rate (MRR), channel characteristics like width, depth, and Surface Roughness (Ra). The machined Channels are found to have sufficient depth and good surface finish and are free from heat affected zone and resolidification. X-Ray Diffraction (XRD) analysis has indicated the presence of embedded SiC particles in the channel. GRA method is utilized to achieve an optimal condition of higher depth and MRR, smaller width, and Ra. Also, the significance and percentage contribution of process parameters are found out through ANOVA and obtained results are presented in the paper.

Influence of RHA reinforcements on mechanical and wear behavior of Al 4032 composites

This study was aimed at developing low-cost composites with high specific strength and better performance by incorporating agro-waste as reinforcements. The stir-casting technique was adopted for fabricating composites with aluminum (Al) 4032 as matrix material and 0, 2, 4 and 6 wt.% rice husk ash (RHA) as reinforcements. The mechanical properties of the produced composites were investigated, and the wear rate under dry conditions was also experimented on, to assess the characteristics of the produced composites. Energy-dispersive X-ray spectroscopy and scanning electron microscopy analyses were done to study the presence and distribution of reinforcements in the matrix material. The surface of specimens after wear test was analyzed from optical microscope images. The influence of process parameters such as reinforcement (wt.%), speed (revolutions per min (rpm)) and load (N) on wear rate was identified, and the parameters were optimized for minimum wear rate using a Taguchi L16 orthogonal array. The percentage contribution of process parameters was obtained by performing analysis of variance. Better results were obtained for composites with 6 wt.% RHA with 84 HRB, 92.30 HV, ultimate tensile strength of 383.73 MPa and ultimate compressive strength of 571.6 MPa. Minimum wear rate was obtained for composites with 6 wt.% RHA at 100 rpm and 10 N. Speed was found to be the most contributing factor, with 72.94%, followed by load, with 13.34%, and weight percentage of reinforcements, with 11.88%.

Estimating percentage contribution of process parameters towards build time of FDM process for components displaying spatial symmetry: a case study

Generative manufacturing is an innovative technology which is almost 30 years old. It has the ability of quickly transforming concept into physical models. The design cycle is contracted manifolds by utilising these techniques. One of a versatile generative manufacturing technique is fused deposition modelling (FDM) which is used for production of robust and economical prototypes. In the present research, effect of percentage contribution of critical process parameters on the build time requirements of the FDM process is examined for the given build volume in Fortus 250MC modeller. ABS P430 cubical and spherical primitives of constructive solid geometry, which display spatial symmetry in a given build volume, are chosen as work piece. Response surface methodology is utilised as the statistical tool for experimental design and modelling. This work is an attempt towards explicitly defining the process parameters which affect the build time and their percentage contribution. It has been established by this research that the percentage contribution of slice height outweighs the effect of air gap and orientation towards the estimation of build time. Other FDM build parameters like width and inclination of rasters as also width of contours contributes relatively less towards the build time and material volume quantities.

Estimating percentage contribution of process parameters towards build time of FDM process for components displaying spatial symmetry: a case study

Estimating percentage contribution of process parameters towards build time of FDM process for components displaying spatial symmetry: a case study

Optimization of process parameters using grey relational analysis and taguchi method during micro-EDMing

Innovation in miniaturization of the products and their applications is a steady growth in various fields of engineering. Micro EDM is one of the most considerable machining processes to fabricate micro holes. In the present experimental work, micro holes have been fabricated on SS-304 using Micro EDM process. The effect of process parameters viz. current, Ton, Toff and flushing pressure on output parameters viz. Material Removal Rate (MRR) and Tool Wear Rate (TWR) have been examined. Taguchi L9 methods and Grey relational analysis are employed to find the best level of process parameters to optimize the micromachining process and analysis of variance (ANOVA), a statistical package, has been applied to reveal the percentage contribution of process parameters on process performance. The investigation shows that the current is the most influencing input process parameter which affects the performance parameters.

Effect of tool pin profile on performance of friction stir welding of brass-copper-based butt welded joint

In the present research work, industrial grade pure copper and brass have been joined using friction stir welding. Effect of tool pin profile along with stirrer rotation speed and welding speed on the friction stir welding performance in terms of breaking load and percentage elongation has been investigated. Three tool pin profiles were designed viz., cylindrical, tapered threaded and square. These were used to fabricate the joints at three different rotation speeds (1,000, 1,100, 1,200 rpm) and welding speeds (25, 35, 40 mm/min.). The experiments were designed according to Taguchi-based L-9 orthogonal array. Variance analysis has been carried out to obtain the influence and percentage contribution of process parameters on welding performance. Optimisation results reveal that most significant factor is the pin profile. Square pin profile at 1,200 rpm along with 35 mm/min welding speed produces mechanically sound and metallurgically defect-free weld joints.

Determination of multi-performance characteristics for powder mixed electric discharge machining of tungsten carbide alloy

This article aims to develop a method that optimize the multi-performance characteristics, that is, micro-hardness and surface roughness of powder mixed electric discharge machining process. For experimentation, four input parameters—(a) pulse-on time, (b) pulse-off time, (c) current and (d) powder—are considered to investigate the improvement in multi-performance characteristics using Taguchi’s L27 orthogonal array design. Furthermore, to optimize these parameters and to handle the element of uncertainty associated with multi-input and discrete data, a method combining the grey and Taguchi experimental design was established. Theoretical prediction of results obtained from grey relational grade approach shows that the proposed approach proved useful for optimizing surface roughness and micro-hardness. In addition, analysis of variance is used to find the percentage contribution of process parameters. Finally, from analytical and experimental results, it is concluded that the pulse-on, powder and current are the most influencing parameters in powder mixed electric discharge machining of cobalt-bonded tungsten carbide.

Multi-Criteria Optimization Using Grey Relational Analysis in Drilling of Glass/Epoxy Polymeric Composites

Glass Fibre Reinforced Polymeric (GFRP) composite materials have been used to make several components in engineering field. This is due to their excellent mechanical properties such as high specific strength, specific stiffness, good fatigue resistance, good corrosion resistance and light weight. Drilling is the process required for these composite materials for fitting and assembly with base part which may generate delamination at entrance and exit. In drilling of GFRP composite, delamination is one of the major defect which is more responsible for the rejection of components in the final assembly of engineering parts. An experimental investigation of full factorial design performed on drilling of Glass Fibre Reinforced plastic laminates using Helical flute straight shank drill and “Brad and Spur” drill by varying the process parameters such as cutting speed and feed rate to find the optimum drilling conditions. The main objective of this paper is to optimize the drilling process parameters with consideration of multiple performances such as specific cutting pressure, power, peel-up delamination factor and push-out delamination factor. Analysis of variance (ANOVA) was carried out for estimating the percentage contribution of process parameters on drilling performance. Grey relational analysis was used in this multiple objective optimization to get damage free drilling of GFRP composite. Response table and graph are used for this analysis which shows that feed rate is the most significant factor than the cutting speed and also it indicates that delamintation free drilling can be obtained at low feed rate and low cutting speed. The result shows that drilling performance can be enhanced effectively thorough this approach.

Prediction of Optimal Process Parameters for Abrasive Assisted Drilling of SS304

This paper presents the optimization of cutting parameters for improving surface finish of stainless steel SS304 in the abrasive assisted drilling. In the present work, drilling of SS304 with supply of abrasive slurry consisting of silicon carbide abrasives of 1250 mesh size has been studied. The slurry concentration has been varied from 20-30% by weight. Abrasives slurry performs the dual function of cutting fluid as well as coolant. Response surface methodology (RSM) has been adopted for planning of experiments. Analysis of variance has been carried out to find out the significance and percentage contribution of process parameters and the interaction among various factors has been observed. The drilling parameters including spindle speed, feed rate, and slurry concentration are optimized using multiple performance characteristics for surface roughness. Although, feed rate and spindle speed are the most significant factors which affect the surface roughness but an overall improvement of approximately 11% in the surface roughness has been witnessed with the aid of abrasive slurry. These research findings provide useful economic machining solution in terms of optimized drilling conditions for drilling stainless steel SS304.