Grey Grade Research Articles

Grey Relational Analysis (GRA) for optimization of CO2 laser cutting of stainless steel

Laser cutting is a non-traditional industrial technique for cutting a variety of materials. The major goal of this study is to examine the influence of variables such as stand off distance, laser beam power, gas pressure and speed of cut on the width of the kerf, hardness, and roughness for CO2 laser cut of stainless steel. For the experimental plan, Taguchi's L9 orthogonal array was used. In the experiment, 4 cutting parameters were used: laser beam power (3400, 3700 and 4000 W), speed of cut (2200, 3100 and 4000 mm/min), gas pressure (0.7, 1and 1.3 bar) and stand off distance (0.6, 0.9, 1.2 mm). Laser cutting of AISI 304 stainless steel with a variety of performance characteristics is addressed using a grey grade derived from grey relational analysis. The grey grade reveal that speed of cut has a greater impact on the responses like hardness, width of the kerf and MRR than laser beam power, gas pressure and standoff distance. With this GRA technique, it is evident that the mentioned laser cutting performance characteristics can be optimized.

MULTI-RESPONSE OPTIMIZATION OF DIELECTRIC FLUID MIXTURE IN EDM USING GREY RELATIONAL ANALYSIS (GRA) IN TAGUCHI METHOD

In the current study, combining the powder with dielectric fluid in electrical discharge machining (PMEDM) is a very fascinating technological approach. This approach is the most effective at increasing both productivity and the quality of a machined surface at the same time. The Taguchi–GRA approach was used to optimize the surface roughness (SR), material removal rate (MRR), and micro-hardness of a machined surface (HV) in electrical discharge machining of die steels in dielectric fluid with mixed powder. Workpiece materials (with 3 levels such as SKD61, SKD11, and SKT4), electrode materials (with 2 levels such as copper, and graphite), pulse-on time, electrode polarity, current, pulse-off time, and titanium powder concentration were all used in the study. The effect on the ideal results was also evaluated using some interaction pairings among the process parameters. Powder concentration, electrode material, electrode polarity, current, pulse-on time, pulse-off time, and Interaction between workpiece material and powder concentration were obtained to be significant in the ideal condition, where larger MRR and HV are wanted (as per the HB criterion), but lower values are desired for the remaining responses, such as surface roughness (SR). Powder concentration was also discovered to be a major component, however, it only accounts for 8.35 percent of the ideal condition. MRR = 54.36 mm3/min, SR = 5.65 m, and HV =832.66 HV were the best quality attributes based on the grey grade.

ACO EUROBAR EN-GJL-250C (5.1203)

Abstract ACO Eurobar EN-GJL-250C (5.1203) is an intermediate-tensile-strength gray cast iron that is produced by the continuous casting process. Compared with the lower strength gray cast iron grade, EN-GJL-200C (5.1202), it possesses superior wear resistance, while still maintaining good thermal conductivity, damping capacity, and machinability. This datasheet provides information on composition, physical properties, microstructure, hardness, and tensile properties. It also includes information on heat treating and machining. Filing Code: CI-94. Producer or source: ACO Eurobar GmbH (a subsidiary of ACO Guss GmbH).

Machining of Ti-6Al-4V biomedical alloy by WEDM: investigation and optimization of MRR and Rz using grey-harmony search

PurposeThe purpose of this paper is to investigate the optimized setting of wire-cut electrical discharge machining (WEDM) parameters at which material removal rate (MRR) and mean roughness depth (Rz) set a compromise. The problem in the processing of Ti-6Al-4V by conventional processes is a high strength, high hardness, high tool wear. Due to which WEDM is adopted to machine Ti-6Al-4V biomedical alloy. Ti-6Al-4V alloy has a number of applications in the engineering and medical industries due to its high strength biocompatibility.Design/methodology/approachThe effect of control factors (i.e. pulse on-time: Pon; pulse off-time: Poff; servo voltage: SV) on the MRR and Rz is investigated in the present research. The planning of experiments is done using a Taguchi-based L9 orthogonal array. The percentage influence of each factor on responses is also evaluated. The multi-objective optimization is done using the grey approach initially. After that, the results were also calculated using harmony search (HS). Therefore, a hybrid approach of grey and HS is used to find the optimized values of MRR and Rz.FindingsThe maximum value of grade calculated by grey-HS is 0.7879, while in the case of the experimental run the maximum value of grey grade is 0.7239. The optimized setting after improvisation at this grade value is Pon: 130 µs; Poff: 45 µs and SV: 70 V for MRR and Rz collectively. The validation of the suggested setting is completed by experimentation. The values of MRR and Rz are coming out to be 6.4 mm3/min and 13.84 µm, which represents improvised results after the implementation of the HS algorithm.Originality/valueThe integration of the grey approach with the HS principle in the manufacturing domain is yet to be explored. Therefore, in the present research hybrid approach of grey-HS is implemented in the manufacturing domain having applications in medical industries.

MEEHANITE GE225

Abstract Meehanite GE225 is an intermediate-tensile-strength gray cast iron that has a predominantly pearlitic matrix and a minimum tensile strength of 225 MPa (33 ksi), when determined on test pieces machined from separately cast, 30 mm (1.2 in.) diameter test bars. Compared with the lower strength gray cast iron grades, Meehanite GE225 contains lower carbon and silicon contents, while still maintaining excellent thermal conductivity, damping capacity and machinability. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on high temperature performance as well as casting, heat treating, machining, and joining. Filing Code: CI-84. Producer or source: Meehanite Metal Corporation.

MEEHANITE GD250

Abstract Meehanite GD250 is an intermediate-tensile-strength, pearlitic gray cast iron grade that has a minimum tensile strength of 250 MPa (36 ksi), when determined on test pieces machined from separately cast, 30 mm (1.2 in.) diameter test bars. Owing to its good machinability it is suitable for mass produced parts for automobiles as well as for small hydraulic bodies that must be pressure tight. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on low and high temperature performance as well as casting, heat treating, machining, and joining. Filing Code: CI-81. Producer or source: Meehanite Metal Corporation.

WITHDRAWN: Impact of Diisopropyl Ether on VCR diesel engine performance and emission with cashew shell oil using GRA approach

Recent research studies have proposed that diesel blended individually with different bio fuels such as cashew shell oil and di-ethylene glycol provide better efficient and emission characteristics. The blends are made with Diisopropyl Ether and cashew shell oil using the L9 Orthogonal array in this experimental analysis review. This research has a significant effect on the specifics of blended fuel with additives and diesel engines. Grey relational processing is used to transform multi-response data into single-response data. A confirmation experiment is used to verify the Initial design factor combination based on the highest ranking of grey grade. The best engine parameter is inferred using the grey method A3B3C1 factors and levels combination.

ISO 185/JL/275

Abstract ISO 185/JL/275 is an intermediate-tensile-strength gray cast iron that has a pearlitic matrix and a tensile strength of 275–375 MPa (40–54 ksi), when determined on test pieces machined from separately cast, 30 mm (1.2 in.) diameter test bars. Compared with the lower strength gray cast iron grades, ISO 185/JL/275 contains lower carbon and silicon contents, while still maintaining good thermal conductivity and damping capacity. Owing to its higher tensile strength and hardness, it exhibits superior wear properties. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and bend strength as well as fatigue. It also includes information on casting and heat treating. Filing Code: CI-79. Producer or source: International Organization for Standardization.

ISO 185/JL/250

Abstract ISO 185/JL/250 is an intermediate-tensile-strength gray cast iron that has a pearlitic matrix and a tensile strength of 250–350 MPa (36–51 ksi), when determined on test pieces machined from separately cast, 30 mm (1.2 in.) diameter test bars. Compared with the lower strength gray cast iron grades, ISO 185/JL/250 contains lower carbon and silicon contents and has superior wear resistance, while still maintaining good thermal conductivity, damping capacity, and machinability. This datasheet provides information on composition, physical properties, and tensile properties as well as fatigue. It also includes information on casting and heat treating. Filing Code: CI-76. Producer or source: ISO Central Secretariat.

ISO 185/JL/225

Abstract ISO 185/JL/225 is an intermediate-tensile-strength gray cast iron that has a predominantly pearlitic matrix, and a tensile strength of 225–325 MPa (33-47 ksi), when determined on test pieces machined from separately cast, 30 mm (1.2 in.) diameter test bars. Compared with the lower strength gray cast iron grades, ISO 185/JL/225 contains lower carbon and silicon contents, while still maintaining excellent thermal conductivity, damping capacity, and machinability. This datasheet provides information on composition, physical properties, tensile properties, and compressive strength as well as fatigue. It also includes information on heat treating. Filing Code: CI-73. Producer or source: International Organization for Standardization (ISO).

ISO 185/JL/200

Abstract ISO 185/JL/200 is an intermediate-tensile-strength gray cast iron that has a predominantly pearlitic matrix, and a tensile strength of 200–300 MPa (29–44 ksi) when determined on test pieces machined from separately cast, 30 mm (1.2 in.) diameter test bars. Compared with the lower strength gray cast iron grades, 185/JL/200 contains lower carbon and silicon contents, while still maintaining excellent thermal conductivity, damping capacity, and machinability. This datasheet provides information on composition, physical properties, tensile properties, compressive and bend strength as well as fatigue. It also includes information on casting and heat treating. Filing Code: CI-70. Producer or source: International Organization for Standardization.

Optimization of Bio Degradable Nano Cutting Fluid Parameters during Machining of Titanium Alloy

Varieties of cutting fluids are available in market to facilitate good machining objectives for metal removing Industries. Eventually, majority of the cutting fluids are synthetic and semi synthetic in nature, despite they are helping to the industries but they are harmful to health of the operators and environment. Though they are having good properties needed for machining, nature of non-biodegradability and non-friendliness to the environment are the key barriers associated with these fluids. Various researches have been carried out to prepare a vegetable based bio degradable effective cutting fluid to nullify above said constraints. In this research work, a unique castor oil based cutting fluid infused with nano molybdenum di sulfide (MoS2) particles has been prepared and its performance during machining has been investigated. In this study, much attention has been applied to achieve the optimized parameters of the biodegradable nano cutting fluid. Taguchi's method equipped with gray relational analysis was utilized by considering the size of the nano particles, nano particle inclusion (npi) and flow rate as the chief fluid parameters. The surface roughness and tool wear were treated as responses. As per L9 orthogonal array, totally nine experiments were conducted. Additionally, the most significant parameter which affects the machining responses was identified with the help of grey grade, ANOVA and MRPI ranking. Confirmation test were carried out followed by prediction of grey grade so as to improve the degree of validation. It has been observed that there was significant improvement in gray grade for the optimal parameters.

Performance of Zinc Coated Electrode Wire and Parametric Optimization During Profile Cutting of Die-Steel

In this work, the effect of brass wire coated with zinc as electrode wire towards maximizing MRR and minimizing SR for the considered input parameters was studied in elaborate during profile cutting of tool steel AISI D3. Experiments were designed based on the L18(21,37) Taguchi’s orthogonal array considering cutting speed, Ton and Toff, wire tension, servo feed rate and voltage, current and electrode feed rate. The outputs MRR and SR were analyzed and optimized using Grey Relational Analysis (GRA) simultaneously. For both SR and MRR, the drawn chart shows that, the raw data’s lies within upper and lower control limits. The optimum input conditions obtained for higher MRR and lower SR were: 75% of cutting speed, 128 μsec of Ton, 54μsec of Toff, 190A of input current, electrode feed of 3 mm/min with 7 gm of electrode tension, 10V of servo voltage and 2060 mm/min of 10V. Execution of ANOVA on grey grade identifies that, wire tension was the parameter that influences more by 25.89%, followed by Ton and servo voltage by 21.37% and feed rate of wire by 11.89%, with an R2 value of 96.55%. For validating the results, confirmation experiment was also done.

大豆主要农艺性状与品质灰色关联度分析

大豆主要农艺性状与品质灰色关联度分析

Multiple performance characteristics Optimization of WEDM by Grey Grade for EN-8

Multiple performance characteristics Optimization of WEDM by Grey Grade for EN-8

Optimization of mechanical/thermal properties of glass/flax/waste cotton hybrid composite

In quest of finding solutions of high cost and non-biodegradability issues of synthetic fibre-based composites, hybridization of natural fibres is a focused approach recently. The current study is focused to find out the optimized proportion of natural recycled fibre with virgin synthetic fibre which offers maximum mechanical properties with low cost. Synthetic/recycled (glass/waste cotton) and synthetic/natural/recycled (glass/flax/waste cotton) hybrid composites were developed and their mechanical and thermal properties were characterized. First, the mechanical properties, i.e. tensile strength, flexural strength and impact strength, that are most important for structural applications were studied. Second, the coefficient of thermal expansion of developed composites was determined. For optimization of the aforesaid properties of the hybrid composites, a statistical tool, i.e. grey relational analysis, was applied. The grey grades show that with the inclusion of waste cotton fibre, there is no significant decrease in mechanical properties, whereas there is a drastic decrease in cost. Furthermore, utilization of waste fibres in the composites is the best solution, as the poor mechanical properties of waste fibre are not as much pronounced in the composite form, thanks to continuous and strong interface of resin with recycled fibres.

Application of fuzzy-assisted grey Taguchi approach for engine parameters optimization on performance-emission of a CI engine

ABSTRACT With the prevalent interest in diesel engine performance and emission, it is necessary to define optimum engine operating condition with less number of experiments for the efficient and effective outcome. In this article, the combined effect of input parameters viz. engine load and types of fuel blend in controlling BSFC, NOx, UHC, and CO output variables in a diesel engine are investigated. In this study, a fuzzy-assisted grey Taguchi method has been proposed to optimize the engine load and types of fuel used. The main purpose of using fuzzy inference system is to convert the multi-response into an equivalent single objective optimization. Optimum input factor corresponding to estimated values of output response has been obtained by employing fuzzy grey reasoning grade. The computed factor combination based on the highest ranking of fuzzy grey grade is validated through a confirmation experiment. Based on grey-fuzzy approach optimum engine parameter is found D85B10E5 at 100% load. ANOVA analysis of Grey Fuzzy Grade reveals engine load is the most significant input factor influencing engine output. Based on the results it is concluded that grey-fuzzy-Taguchi approach can be a more useful tool to ameliorate performance and emission of an engine compared to simple grey relational grade.Abbreviations: CI: compression ignition; BSEC: break specific energy consumption; NOx: nitrogen oxides; UHC: unburned hydrocarbon; CO: carbon monoxide; GRA: grey relational analysis; GRC: grey relational coefficient; GRG: grey relational grade; ANOVA: analysis of variance; DAQ: data acquisition; S/N: signal to noise ratio; FIS: fuzzy interface system; GFG: grey fuzzy grade

Financial performance assessment using Grey relational analysis (GRA)

PurposeTraditional statistical methods to study the financial performance of any industry have many barriers and limitations in terms of the statistical distribution of the financial ratios, and, in particular, it considers only its positive values of it. The purpose of this paper is to estimate the financial performance of 24 Indian life insurance companies for the period from 2013 to 2016 using Grey relational analysis (GRA) proposed by Deng (1982) that accommodates the negative values in the analysis.Design/methodology/approachFinancial performance of 24 Indian life insurance companies for the years from 2013–2014 to 2015–2016 is examined using a total of 14 indicators from capital adequacy ratios, liquidity ratios, operating ratios and profitability ratios (PR). The methodology used is GRA to obtain the Grey grades to rank the performance indicators, where higher relational grade shows better financial performance, and a lower score depicts the scope for improving the performance.FindingsThe results rank the insurance companies according to their financial performance in which Shriram insurance stands first with higher relational grade score, followed by the companies like IDBI Insurance, Sahara Insurance and Life Insurance Corporation of India. The main finding is that PR which have negative values are playing a crucial role in determining the financial performance of Indian life insurance companies.Practical implicationsThis study has far-reaching practical implications in twofold: first, for the Indian life insurance industry, they have to concentrate more on PR for better financial health and, second, for any financial performance analysis, ignoring negative value ratios produce biased inference and GRA can be used for better inference.Originality/valueThis study is the first attempt to evaluate the financial performance of Indian life insurance using the GRA methodology. The advantage of GRA is that there is no restrictions on the statistical distribution of the data and it also accommodates the negative values, whereas all the other traditional methods insist on the statistical distribution of data, and, more importantly, they cannot handle negative values in the performance analysis.

Selection of optimal glazing material for solar thermal applications using grey relational analysis

ABSTRACT This article deals the selection of optimal glazing materials for solar thermal applications with multiple performance characteristics among the twelve alternatives using the Taguchi's grey relational analysis approach. The processing parameters thermal properties, mechanical properties, optical properties, environmental and economic conditions are optimised with multi-response characteristics, including density, thermal conductivity, specific heat capacity, the coefficient of thermal expansion, notch impact strength, tensile strength, refractive index, transmittance, cost, and environment. In this investigation, twelve alternative materials and ten criteria used for material selection for the optimal design. The outcomes revealed that crystal glass has the highest grey grade of 0.588, which is the optimal glazing material among the twelve alternatives.

Are there ancient soils in the 3.7 Ga Isua Greenstone Belt, Greenland?

A lens of black schist within 3.7 Ga quartzites of Greenland may be Earth's oldest known alluvial paleosol. The suspect metamorphic rock is a lens in orthoquartzite of berthierine schist with crystals of ripidolite, but it has a truncated top above dark gray grading down to gray color, ptygmatically folded surface cracks filled with silt grains, and large sand crystals, unusual for sedimentary or metamorphic rocks. The paleosol hypothesis was tested with thin sections showing plausible mineral weathering trends, and by chemical analysis showing molar weathering ratios and REE distribution like those of soils. The schist is deeply weathered and at the culmination of weathering trends from analysis of other metasediments of the Isukasia area. The protolith can be reconstructed as a saponite clay with a salt-rich horizon of kieserite, like other acid-sulfate paleosols of the early Earth. Models for proton and electron consumption of paleosols applied to the profile reveal an atmosphere with only 36 ± 510 ppm O2 and 820 ± 201 ppm CO2, and humid, cool temperate paleoclimate. The profile has organic δ13CPDB consistently of −24.2 to −27.4‰, and modest Raleigh distillation near the top. Similar consistent values and trends are produced by decay of organic matter in living soils, but biotic carbon isotopic composition of sediments is erratic from bed to bed, and abiotic carbon compounds of meteorites differ dramatically for each kerogen particle. Thus life in this very ancient soil is not precluded by our analyses, but ultrastructural and geochemical testing of carbon particles would further test this hypothesis.