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Ultrasonic Assisted Electro-spark Deposition Equipment And Processing Research

Posted on:2012-05-17Degree:MasterType:Thesis
Country:ChinaCandidate:Y XuFull Text:PDF
GTID:2131330335974479Subject:Mechanical Manufacturing and Automation
Abstract/Summary:PDF Full Text Request
In the course of working, die will out of work for normal or abnormal failures. In this paper, firstly analyze common failure modes of cold mold, hot die, non-metallic mold and die casting mold, and further study the repairable failure modes. And then introduce the argon arc welding, general discharge cold welding, laser welding technology, brush plating method and electro-spark deposition (ESD) technology. In addition, analyze the principle, advantages, disadvantages and applications of ESD processing. For ESD technology exist sediment thickness too small, inefficient, easily appear "anode adhesion" phenomenon and other bottlenecks, our research team creatively put forward the ultrasound-assisted electro-spark deposition and ultrasonic polishing process, and developed a set of integrated equipment. A series of repairing deposition, surface hardening experiments were carried out, and the performance of sedimentary layer and enhancement layers were studied.Machining mechanism is a pivotal part in any process, and it is also a theoretical foundation of any process. Therefore, the mechanisms of the ultrasound-assisted electro-spark deposition and ultrasonic polishing process were analyzed. And make sure it is using pulse power with short pulse width, high frequency, high energy density and high frequency ultrasound energy, to penetrating conductive material of the tool into the melting substrate surface, then forming metallurgy combined coating. The deposited coating can improve the substrate surface physical, chemical and mechanical properties. The introduction of ultrasonic can effectively improve the gap discharge state, reduce the "anode adhesion" phenomenon and promote the nucleation rate. Thereby, reduce the short circuit, arcing phenomena, improve the process of deposition, and optimize the performance of sedimentary layers.Experimental researches on ultrasonic assisted ESD and ultrasonic polishing process were carried out. These experiments were conducted in many aspects to explore the effects of machining parameters, such as, the polarity effect, electrical parameters, different materials of electrode and as well as the type of shielding gas, on the thickness of deposition coatings. Some basic laws of ultrasonic electric spark deposition and ultrasonic polishing have been discovered through these experimental works. These experimental phenomena and results were deeply analyzed and summarized.Repairing coating was obtained on the surface of H13 steel and 718 steel via ultrasonic assisted electro-spark deposition. These experimental studies show that the discharge voltage, discharge frequency, the deposition ratio, argon gas flow and electrode speed were a certain impact on the coating thickness. And the theoretical optimum parameters that are conducive to improving coating thickness were determined. SUS304 stainless steel and CuCrl alloy surface hardening experiments show that hardened layer can be obtained by Ultrasonic assisted ESD process. Moreover, the micro-hardness, wear resistance, corrosion resistance and other properties of deposition coating were superior to untreated surface. Thus, this study has a certain practical significance on mould re-manufacturing technology. In addition, this study provided a novel way to extend the life of common molds and micro-spot welding electrodes.
Keywords/Search Tags:Ultrasound, Electro-spark deposition (ESD), Integrate devices, Repairable, Re-manufacturing technology, Strengthening
PDF Full Text Request
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