Because of the exceptional physical, chemical, electric and mechanical properties of hard and brittle materials, such as ceramics, glass and diamond film etc, those are considerably valued in high technology industry. Although those materials can be machined using the ECDM method, its machining mechanism is still indeterminate. In this study, a static electrical pitting tester is employed, the electrolyte is KOH(eq), the workpiece is glass, and we change the parameters, such as supply voltage, supply current and machining gap to investigate the mechanism of static Electrochemical Discharge Machining. From the experimental results, which are SEM pictures of machined glass and variations of current, we can clearly infer the mechanism of static-ECDM. Moreover, the most important reason for damaging glass is supply voltage. Even increasing supply voltage can make glass cleave. And the main factor to make the loop become insulating is supply current. While the supply voltage is 50V, the supply current is 8A, and in different machining gap condition, the results show that it has a certainly gap to discharge during the machining process, and the particular gap is about 49£gm. The results also show that the machining model has two kinds of types. When the machining gap is shorter than 49£gm, the machining model is from ring to circle; contrarily, when it is longer than 49£gm, the machining model is circle directly.

Because of the exceptional physical, chemical, electric and mechanical properties of hard and brittle materials, such as ceramics, glass and diamond film etc, those are considerably valued in high technology industry. Although those materials can be machined using the ECDM method, but mostly used for machining hole and wire cutting, there is few application in the polishing aspect. In this study, a high-precision dynamic electrical pitting tester is employed, the electrolyte is KOH(eq), investigate the behavior of static electrochemical discharge of supply voltage and electrolyte highly to the steel ball/glass, and analysis it¡¦s machining characteristic. From the experimental results, which are SEM pictures of machined glass and variations of current and force , we can clearly infer the electrochemical discharge machining mold, and establish electrochemical I-V curve under different electrolyte highly, and furthermore machining area classify for (1) non-machining district (2) precision machining district (3) middle machining district (4) heavy machining district. The experimental results shows, the pitting of damage width and depth and supply voltage are relation in direct ratio. Under three different electrolytes highly, shows the critical voltage of pitting damage are all the same value, namely 29V, and electrolyte highly will be influenced real machining time and damaged form of surface. In the precision machining district, can get the surface roughness (Ra) reach 0.02£gm, machining depth of surface damage reach 0.3649£gm after machined for 60 seconds under the optimum operating parameter.

A static electrochemical discharge machining (ECDM) tester, where the tungsten needle is used as the cathode and the platinum as the anode and the glass as the specimen, and the depth of electrode is set to be 1mm in the aqueous electrolyte of 30wt% KOH at the test time of 10s, is employed to investigate the influence of geometry and size of the electrode, supply voltage and gap on the characteristic of electrochemical discharge machining. According to the current/voltage measurements combined with the photographs of the bubble layer on the cathode and the behavior of discharge under different geometry and size of the electrode during the ECDM process, three regimes have been identified as: (I): non-machining. (II): glow discharge. (III): spark discharge. From the observation on the surface of machined glass specimen by using SEM, the experimental result show that damage of the glass increases with the increase of supply voltage.

The exceptional physical, chemical, electric, and mechanical properties of ceramics, glass and diamond film make them receive much attention in high-tech industry. Although the electrochemical discharge machining (ECDM) can be used to process those materials, most ECDM are used for machining micro-holes and wire cutting. However, the application on the polishing aspect is still scarce in the literature. In this study, a high-precision dynamic electrical pitting tester with the electrolyte of KOH is employed to investigate the behavior of static electrochemical discharge in terms of supply voltage and gap distance between the steel ball and the diamond film. Furthermore, its machining characteristics are also analyzed. According to the current waveform, the I-V curve is plotted. Results show that the current value of glass is higher than that of diamond film and acrylic. This indicates that the glass is easily to be ionized. According to the observation on the surface of machined diamond film by using SEM, the machined status can be divided into four regimes. In the first regime, the supply voltage is less than 100V where the machined mark on the diamond film cannot be found. Hence, it is called non-machined regime. In the second regime, the supply voltage is in the range between 100 and 107V, where only very slight damage can be observed on the diamond film. Hence, it is called the fine machined regime. In the third regime, the supply voltage is in the range between 107 and 110V, where the machined status on the diamond film is unstable. Hence, it is called the transition regime. In the fourth regime, the supply voltage is larger than 110V, where the machined damage is very heavy. Hence, it is called the rough machined regime. At the supply voltage 105V with the gap less than 80£gm, the annular shape of the machined damage on the surface of the diamond film can be observed. However, when the gap is in the range between 80£gm and 95£gm, the annular shape of the machined damage disappears, but there is still slight damage at the asperity of the diamond film. When the gap is larger than 95£gm, the machined damage is invisible. Hence, the critical gap is defined as 95£gm for the supply voltage of 105V. At the supply voltage of 105V, the gap of 90£gm, and the machining time of 10 min, only the asperity of diamond film shows machined mark, but the surface is flatter. Therefore, it is possible to conduct the fine machining process by using ECDM on diamond film.

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Due to increasing interest in sustainable development, today s engineer is often tasked with designing systems that are environmentally benign over their entire life cycles. Unfortunately, environmental assessments commonly suffer from significant uncertainty due to lack of information, particularly for time-distant life cycle aspects. Under severe uncertainty, traditional uncertainty formalisms require more information than is available. However, a recently devised formalism, information-gap decision theory (IGDT), requires no more information than a nominal estimate; error bounds on that estimate are unknown. The IGDT decision strategy, accordingly, favors the design that is robust to the most estimation error while still guaranteeing no worse than some good enough critical level of performance. In some cases, one can use IGDT to identify a preferable design option without needing more information or more complex uncertainty analysis. In this dissertation, IGDT is investigated and shown to enhance decision support for environmentally benign design and manufacturing (EBDM) problems. First, the applicability of the theory to EBDM problems is characterized. Conditions that warrant an info-gap analysis are reviewed, the insight it can reveal about design robustness is demonstrated, and practical limitations to its use are revealed. Second, a new mathematical technique is presented that expands capabilities for analyzing robustness to multiple info-gap uncertainties simultaneously. The technique elicits scaling factors more rigorously than before and allows one to imprecisely express their beliefs about info-gap scaling. Two examples problems affected by info-gaps are investigated: oil filter selection and remanufacturing process selection. It is shown that limited information about uncertainty can, in some cases, indeed enable one to identify a most preferable design without requiring more information.