dc.description.abstract | Electrochemical jet machining (ECJM) is one of the non-traditional machining technologies, the technology is by metal material removing through electrochemical reaction, the dissolved metal were carried away via jet flow from machining region. However, The process of abrasive slurry-jet machining (ASJM) is that erodes material using abrasive particles by a steam of fluid impinging on a target. ECJM has several advantages, such as difficult to wear electrode, removing part of workpiece by dissolved via jet, no residual stress and Metamorphic layer, high machining rate and good smoothness on machining surface.
In this thesis, the object of research is to combine ECJM and ASJM. Due to the unique technology of electrochemical machining, it is usually applied to other conditions which mechanics is hard to machine. However, when the electrochemical technology applies to machine carbon steel or the material which have been heat treatment, the black layer will be generated on the surface, that is Carbon-rich layer. This layer is not the products of the electrochemical reaction, but the iron in ions fall after leaves from the surface of workpiece. Because the carbon is active, it is easy to deposit to the surface of workpiece, and it is not easy to depart by electrolyte flow in general electrochemical machining method. Moreover, this layer will obstruct electrochemical machining, so it causes the lower rate of machining and more roughness on the surface after machining.
In view of these, we proposed a project that is to machine and clear burr on SKD11 by ASJM. We can overcome the obstruction of blacklayer in the physical erosion and electrochemical corrosion, so as to increase the efficiency of machining and decrease the roughness of the surface.
In this thesis, the hollow tube is used in 500 and 700μm, and the NaCl is chosen as the electrolyte to drill SKD11, and investigate the influence of different voltage, concentration, abrasive concentration, gap and flow. Moreover, we compare the effective height and aspect ratio to choose the best parameters, and make an object to machine a hole of 1000μm, and compare the difference if ECJM with abrasive or not.
The results show that the best effective occurs when voltage in 70V and NaCl concentration in 20%, gap in 1mm and the flow in 340ml/min. And no matter roughness or material removal, ECJM assisted with abrasive is better than ECJM only. | en_US |