A Study of Influence of Electrolyte Composition on ECH of Bevel Gears using Mixture D-Optimal Design
This paper discusses the experimental investigation to find out the optimal electrolyte composition in improving the surface quality of the gear teeth profile during surfacing finishing of bevel gears by the electrochemical honing process. In this study, AISI 1040 was used as the workpiece material, mixtures of sodium chloride and sodium nitrate in different ratios were used as the input parameter, and the percentage improvement in the surface roughness and material removal rate of the process were used as measures of process performance. The experimental runs were designed according to the Mixture DOptimal design. The analysis of the experimental outcome was carried out and 80% NaCl + 20% NaNO3 was found to be theoptimal electrolyte composition to conduct the confirmation experiments. The finding of the study establishes the process for precision finishing of bevel gears.
Investigations on precision finishing of helical gears by electrochemical honing process
Abstract This paper presents the findings of an investigation into the effects of finishing time, electrolyte-related parameters (i.e. electrolyte temperature, composition, and concentration), voltage, and rotating speed of the workpiece on the improvement of surface quality of helical gear teeth finished by the electrochemical honing (ECH) process. Percentage improvement in average surface roughness PIR a and maximum surface roughness PIR tm, three-dimensional plots of the finished surface texture, and microhardness have been used as the measures of ECH process performance. The effects of finishing time, electrolyte temperature, and electrolyte composition have been studied through pilot experiments by varying one variable at a time, while the effects of voltage, rotating speed of the workpiece gear, and electrolyte concentration have been studied during the main experiments designed using the Box–Behnken response surface methodology approach. Scanning electron microscopy and optical profilometry before and after ECH have been used to highlight the improvement in surface quality of helical gears. A special type of cathode gear has been developed by sandwiching a conducting copper gear between two insulating gears of Bakelite, having the capability of varying the rate of electrolytic dissolution steplessly along the full profile of the workpiece gear made of EN8. Based on the results of pilot experiments, 7.5 min as finishing time, a mixture of NaCl and NaNO3 in a ratio of 3:1, and 32 °C as electrolyte temperature were found to be optimum for precision finishing of helical gears. Using the results of main experiments, regression models have been developed for the measures of process performance (i.e. PIR a and PIR tm). Analysis of variance done at the 95 per cent confidence level, to test the significance of the developed models and process variables, found that the developed models are highly significant and that voltage and electrolyte concentration have significant effects on the responses. However, no significant interaction effect has been observed. Predictions from the regression models have been validated by comparing them with the results of the confirmation experiments, which proved that the developed models are correct and acceptable.
Using Infrared Thermography to Detect Moisture in Historic Masonry: A Case Study in Indiana
Nondestructive testing mapped water infiltration in the decoratively painted interior of a Masonic Temple in Muncie, Indiana.