http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Ajay Batish,Anirban Bhattacharya,Manwinder Kaur,Manjot Singh Cheema 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.5
The present study reports the effect of different process parameters on machining forces, surface roughness, dimensional deviation and material removal rate during hard turning of EN31, SAE8620 and EN9 tool steels. Feed rate followed by hardness, cutting speed and nose radius-depth of cut significantly affected machining forces whereas feed rate had the largest effect on surface roughness. The four responses were subsequently optimized for both rough and finish machining using genetic algorithm to determine the optimum combination of input parameters. Machined surfaces were subsequently analyzed using XRD followed by analysis of grain size and crystallite size of the machined samples and SEM analysis. Higher chromium content was observed at the machined surface as manganese dissolves in cementite and may replace iron atoms in the cementite lattice after machining. High heat is generated when machining at higher cutting speeds causing severe strain. The depth of the white layer decreases with increasing tool nose radius and increases at larger feeds because of greater heat generation. The SEM observations showed a smooth pattern with very low undulations with almost no crack damage.
Anirban Bhattacharya,Ajay Batish,Naveen Kumar 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.1
The present study reports the results of an experimental work carried out to evaluate the improvement in machined surface properties of die steels machined using powder mixed electric discharge machining (PMEDM) process. Two surface responses, surface finish and microhardness were analyzed for changes when machined with Si, W and graphite powders mixed in dielectric fluid. The machined surfaces were subsequently analyzed using Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) to study the element migration from powder, dielectric and the tool. The powder mixed with dielectric and its concentration, current and pulse on time were identified as the significant factors affecting surface finish. Brass electrode and tungsten powder resulted in good surface finish. Amongst the dielectrics used, kerosene provided a better cooling effect whereas EDM oil resulted in better surface finish. The microhardness of the machined surface was also affected by powder and its concentration, current, pulse on time and electrode material. W-Cu electrode and W powder resulted in a higher microhardness. The SEM and EDS analysis showed significant migration of material from the suspended powder, electrode and dielectric to the machined surface.
Sanjeev Kumar,Ajay Batish,Rupinder Singh,T. P. Singh 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.7
In the present study, electric discharge machining process was used for machining of titanium alloys. Eight process parameters werevaried during the process. Experimental results showed that current and pulse-on-time significantly affected the performance characteristics. Artificial neural network coupled with Taguchi approach was applied for optimization and prediction of surface roughness. Theexperimental results and the predicted results showed good agreement. SEM was used to investigate the surface integrity. Analysis formigration of different chemical elements and formation of compounds on the surface was performed using EDS and XRD pattern. Theresults showed that high discharge energy caused surface defects such as cracks, craters, thick recast layer, micro pores, pin holes, residualstresses and debris. Also, migration of chemical elements both from electrode and dielectric media were observed during EDS analysis. Presence of carbon was seen on the machined surface. XRD results showed formation of titanium carbide compound which precipitatedon the machined surface.
Pattnaik, P.,Grover, Sunita,Batish, V.K. Asian Australasian Association of Animal Productio 2001 Animal Bioscience Vol.14 No.6
The study evaluated different synthetic and semisynthetic media for maximal recovery of rumen bacteria and expression of their antibacterial activity. Rumen Glucose Cellobiose Agar (RGCA) medium was found to be the best for recovery of rumen bacteria. However, L-10 medium was the best for expression of antibacterial activity of ruminal isolates followed by Easy, M-10, RGCA and M-98-5 medium. The present study recommends the use of L-10 medium as the medium of choice for screening of antibacterial activity of ruminal isolates. Comparative evaluation of bacterial counts on different dietary regimes indicated significant difference between different growth media on a specific diet and between diets on specific growth media within a species. However, there is no overall significant difference between total bacterial counts obtained from rumen liquor of cattle and buffalo with respect to either the feeding regime or growth media. Feeding straw based diet to the animal is the best for high recovery of rumen bacteria.