This work,examines the Surface Roughness(SR)of composite consisting Aluminium alloy(AA6061),Magnesium and Rock dust during turning process.To study the performance,three different test specimens with different constit...This work,examines the Surface Roughness(SR)of composite consisting Aluminium alloy(AA6061),Magnesium and Rock dust during turning process.To study the performance,three different test specimens with different constituents of Al 6061-T6,AZ31 and Rock dust were prepared by stir casting method.Turning experiments were carried out using MTAB Siemens-CNC lathe.The input parameters for machining are speed,depth of cut&feed and output response is surface roughness For each test specimen,there are 15 turning operations were performed using Box-Ben hen Design approach.To analyze the process parameters for SR,the models of ANOVA and Decision Tree(DT)algorithms were performed.Both algorithms are confirmed that,speed is the most significant factor for SR.The addition of AZ 31 with 1%and rock dust of 2%in AA6061 produced better surface finish.Regression models of linear regression,multilayer perception and support vector regression from data science were formulated to find the relationship between variables.Among these models multi layer perception produced minimum root mean square error.展开更多
The cold upsetting studies were carried out for the aluminium metal matrix hybrid composites in the present study. Aluminium metal matrix hybrid composites were synthesised through powder metallurgy route from ball-mi...The cold upsetting studies were carried out for the aluminium metal matrix hybrid composites in the present study. Aluminium metal matrix hybrid composites were synthesised through powder metallurgy route from ball-milled powders to yield the following compositions：Al ＋ 2.5 wt% TiO2＋ 2 wt% Gr, Al ＋ 2.5 wt% TiO2＋ 4 wt% Gr, Al ＋ 5.0 wt% TiO2＋ 2 wt% Gr and Al ＋ 5.0 wt% TiO2＋ 4 wt% Gr. The compaction process was carried out using suitable punch and die in 40 k N hydraulic press, and sintering was done in an electric muffle furnace at the temperature of 590 °C for 3 h. The sintered preforms were subjected to incremental compressive loading of 10 k N until the cracks were found at the free surface. The true axial stress, true hoop stress, true hydrostatic stress and true effective stress were calculated for all the preforms, and all these stresses are correlated with the true axial strain. The stress ratio parameters（rz/reff, rh/reff, rz/rmand rh/rm） of the all preforms were correlated with true axial strain. The maximum true axial stress, true hoop stress, true effective stress and hydrostatic static stress are obtained for the composite containing5 wt% of TiO2 and 4 wt% of graphite and the minimum ones are obtained for composite containing 2.5 wt% of TiO2 and 2 wt% of graphite.展开更多
Aluminium-based metal matrix composites were synthesized from Al-TiO2-Gr powder mixtures using the powder metallurgy technique and their forming characteristics were studied during cold upsetting. Green cylindrical co...Aluminium-based metal matrix composites were synthesized from Al-TiO2-Gr powder mixtures using the powder metallurgy technique and their forming characteristics were studied during cold upsetting. Green cylindrical compacts of pure Al, Al-5wt%TiO2, Al-5wt%TiO2-2wt%Gr, and Al-5wt%TiO2-4wt%Gr were made using a 400-kN hydraulic press equipped with suitable punch and die and by sintering at （590 ± 10）°C for 3 h. Cold upset forging tests were carried out, the true axial stress （σz）, the true hoop stress （σ？）, and the true hy-drostatic stress （σm） were evaluated and, their behavior against the true axial strain （εz） was also analyzed. It is observed that the addition of 5wt%TiO2 into the Al matrix increasesσz,σ？, andσm. The addition of both TiO2 and Gr reinforcements reduces the densification and defor-mation characteristics of the sintered preforms during cold upsetting. Microstructure analyses of the as-sintered and cold upset forged speci-mens also were carried out to substantiate the experimental results.展开更多
This case study has made an effort to show the impact of improved ocean initial conditions(ICs)in a coupled forecast system(CFSv2)simulation on the seasonal prediction of Indian summer monsoon rainfall(ISMR).CFSv2 is ...This case study has made an effort to show the impact of improved ocean initial conditions(ICs)in a coupled forecast system(CFSv2)simulation on the seasonal prediction of Indian summer monsoon rainfall(ISMR).CFSv2 is used as an operational dynamical model for the seasonal prediction of ISMR.Here,we show an improved ISMR skill by initializing the ocean component of CFSv2 using new improved ocean ICs based on Global Ocean Data Assimilation System(GODAS)analysis.This new analysis is better than the NCEP GODAS,which uses the earlier-generation ocean model MOM4p0d and assimilates observed temperature and synthetic salinity using the 3DVar assimilation scheme.However,the new,improved GODAS analysis uses the MOM4p1 ocean model and assimilates observed salinity instead of synthetic salinity.We performed twin sets of nearly identical model experiments differing only in their ICs,with one set using NCEP ICs and the other using the new ICs(NIC).The NIC experiment consistently shows better El Niño-Southern Oscillation prediction skill than the NCEP IC experiment.This advancement leads to improvement in the ISMR skill.We found that the substantial improvements in both oceanic and atmospheric variables in a coupled feedback system contributed to the improved ISMR skills.The enhanced ISMR skill score of the NIC experiment might be the result of improved teleconnections,better depiction of large-scale monsoon circulations,and reduced model drift.展开更多
文摘This work,examines the Surface Roughness(SR)of composite consisting Aluminium alloy(AA6061),Magnesium and Rock dust during turning process.To study the performance,three different test specimens with different constituents of Al 6061-T6,AZ31 and Rock dust were prepared by stir casting method.Turning experiments were carried out using MTAB Siemens-CNC lathe.The input parameters for machining are speed,depth of cut&feed and output response is surface roughness For each test specimen,there are 15 turning operations were performed using Box-Ben hen Design approach.To analyze the process parameters for SR,the models of ANOVA and Decision Tree(DT)algorithms were performed.Both algorithms are confirmed that,speed is the most significant factor for SR.The addition of AZ 31 with 1%and rock dust of 2%in AA6061 produced better surface finish.Regression models of linear regression,multilayer perception and support vector regression from data science were formulated to find the relationship between variables.Among these models multi layer perception produced minimum root mean square error.
文摘The cold upsetting studies were carried out for the aluminium metal matrix hybrid composites in the present study. Aluminium metal matrix hybrid composites were synthesised through powder metallurgy route from ball-milled powders to yield the following compositions：Al ＋ 2.5 wt% TiO2＋ 2 wt% Gr, Al ＋ 2.5 wt% TiO2＋ 4 wt% Gr, Al ＋ 5.0 wt% TiO2＋ 2 wt% Gr and Al ＋ 5.0 wt% TiO2＋ 4 wt% Gr. The compaction process was carried out using suitable punch and die in 40 k N hydraulic press, and sintering was done in an electric muffle furnace at the temperature of 590 °C for 3 h. The sintered preforms were subjected to incremental compressive loading of 10 k N until the cracks were found at the free surface. The true axial stress, true hoop stress, true hydrostatic stress and true effective stress were calculated for all the preforms, and all these stresses are correlated with the true axial strain. The stress ratio parameters（rz/reff, rh/reff, rz/rmand rh/rm） of the all preforms were correlated with true axial strain. The maximum true axial stress, true hoop stress, true effective stress and hydrostatic static stress are obtained for the composite containing5 wt% of TiO2 and 4 wt% of graphite and the minimum ones are obtained for composite containing 2.5 wt% of TiO2 and 2 wt% of graphite.
文摘Aluminium-based metal matrix composites were synthesized from Al-TiO2-Gr powder mixtures using the powder metallurgy technique and their forming characteristics were studied during cold upsetting. Green cylindrical compacts of pure Al, Al-5wt%TiO2, Al-5wt%TiO2-2wt%Gr, and Al-5wt%TiO2-4wt%Gr were made using a 400-kN hydraulic press equipped with suitable punch and die and by sintering at （590 ± 10）°C for 3 h. Cold upset forging tests were carried out, the true axial stress （σz）, the true hoop stress （σ？）, and the true hy-drostatic stress （σm） were evaluated and, their behavior against the true axial strain （εz） was also analyzed. It is observed that the addition of 5wt%TiO2 into the Al matrix increasesσz,σ？, andσm. The addition of both TiO2 and Gr reinforcements reduces the densification and defor-mation characteristics of the sintered preforms during cold upsetting. Microstructure analyses of the as-sintered and cold upset forged speci-mens also were carried out to substantiate the experimental results.
文摘This case study has made an effort to show the impact of improved ocean initial conditions(ICs)in a coupled forecast system(CFSv2)simulation on the seasonal prediction of Indian summer monsoon rainfall(ISMR).CFSv2 is used as an operational dynamical model for the seasonal prediction of ISMR.Here,we show an improved ISMR skill by initializing the ocean component of CFSv2 using new improved ocean ICs based on Global Ocean Data Assimilation System(GODAS)analysis.This new analysis is better than the NCEP GODAS,which uses the earlier-generation ocean model MOM4p0d and assimilates observed temperature and synthetic salinity using the 3DVar assimilation scheme.However,the new,improved GODAS analysis uses the MOM4p1 ocean model and assimilates observed salinity instead of synthetic salinity.We performed twin sets of nearly identical model experiments differing only in their ICs,with one set using NCEP ICs and the other using the new ICs(NIC).The NIC experiment consistently shows better El Niño-Southern Oscillation prediction skill than the NCEP IC experiment.This advancement leads to improvement in the ISMR skill.We found that the substantial improvements in both oceanic and atmospheric variables in a coupled feedback system contributed to the improved ISMR skills.The enhanced ISMR skill score of the NIC experiment might be the result of improved teleconnections,better depiction of large-scale monsoon circulations,and reduced model drift.
