Micro fabrication of freeform surface parts made of hard and brittle materials is always a tough job in micro machining field. This paper tries to fabricate freeform surface feature by using smooth surface of tool ele...Micro fabrication of freeform surface parts made of hard and brittle materials is always a tough job in micro machining field. This paper tries to fabricate freeform surface feature by using smooth surface of tool electrode after tool wear in micro EDM. According to the skin effect theory, the tool end shape in the stage of uniform wear can be changed by adjusting the frequency of discharge pulse. The electrical energy distributing rule of tool electrode section in RC circuit has been investigated under the influence of skin effect, and the law of spark location change has been summarized. The experimental studies demonstrate that different shapes of tool ends can be achieved by varying the pulse frequencies of discharge power supply. Additionally, a micro part of freeform surface feature with high precision and good surface quality has been successfully obtained by micro EDM through adopting the smooth surface after tool wear.展开更多
This paper presents investigations on discharging mechanism in powder mixed EDM.By analyzing the inception,growth of electrical tree and the ignition of discharges in liquid filled gap,the whole discharging process is...This paper presents investigations on discharging mechanism in powder mixed EDM.By analyzing the inception,growth of electrical tree and the ignition of discharges in liquid filled gap,the whole discharging process is proposed.It is explored that the reason of modification of ignition behaves by adding fine particle powders of metal or semiconductor to the working liquid.展开更多
基金Supported by the National Natural Science Foundation of China （50635040） and the National Science Foundation of USA（CMMI-0728294 and CMMI- 0928873）
文摘Micro fabrication of freeform surface parts made of hard and brittle materials is always a tough job in micro machining field. This paper tries to fabricate freeform surface feature by using smooth surface of tool electrode after tool wear in micro EDM. According to the skin effect theory, the tool end shape in the stage of uniform wear can be changed by adjusting the frequency of discharge pulse. The electrical energy distributing rule of tool electrode section in RC circuit has been investigated under the influence of skin effect, and the law of spark location change has been summarized. The experimental studies demonstrate that different shapes of tool ends can be achieved by varying the pulse frequencies of discharge power supply. Additionally, a micro part of freeform surface feature with high precision and good surface quality has been successfully obtained by micro EDM through adopting the smooth surface after tool wear.
基金Funded by the National Natural Science Foundation of China and China Academy of Engineering Physics(No.10276009)
文摘This paper presents investigations on discharging mechanism in powder mixed EDM.By analyzing the inception,growth of electrical tree and the ignition of discharges in liquid filled gap,the whole discharging process is proposed.It is explored that the reason of modification of ignition behaves by adding fine particle powders of metal or semiconductor to the working liquid.
