Bulk nanostructure and amorphous metallic components using the electrospark welding process

Abstract

Purpose -The purpose of this paper is to outline the feasibility of using the electrospark welding (ESW) process to free-form metallic components with nanostructured or amorphous microstructures. Design/methodology/approach -ESW was used to deposit amorphous and nanostructure coatings for high-wear resistance applications. The ESW process was also used to freeform three-dimensional objects via multiple deposition passes. The near-net shape capability is interesting as it significantly reduces the post-processing operations. Findings -This paper demonstrates that it is possible and economically feasible to produce components possessing metastable structures, i.e. nano or amorphous, using the ESW process. Practical implications -The ESW process possesses the ability to manufacture advanced materials and can pattern surfaces to provide appropriate functionality with respect to the service environment. Originality/value -This paper represents a summary of the capabilities of ESW to fabricate advanced materials and is based on the achievements of our laboratory. In particular, results on ESW of amorphous materials and the ability to produce coatings with second phase particles refined to this extent have not been achieved using other manufacturing methods.

Study of the Direct Metal Deposition of AA2024 by ElectroSpark for Coating and Reparation Scopes

“…An electrical arc (due to discharge of capacitor) is pulsed between a rotating consumable electrode (anode) and the work piece/substrate (cathode) to produce the deposit by detaching small droplets of material from the electrode and ejecting towards substrate. Pulse frequencies of a few kilohertz, combined with pulses duration in the 1-10 µs range allow substrate heat dissipation over~99% of the duty cycle [1,14]. The low net heat input into the substrate, and the ability to bond the deposition to the substrate without metallurgical changes in the heat sensitive substrate are among the advantages of the ESD process [15,16].…”

Effect of ElectroSpark Process Parameters on the WE43 Magnesium Alloy Deposition Quality

“…Others researchers studied in detail the mass transfer mechanism in the ESD process. In particular, Gallinov and Luban have developed a method to determine the efficiency of mass transfer, also called transfer coefficient, constantly monitoring the erosion of the anode and the mass gain of the cathode [34].…”

Repairing 2024 Aluminum Alloy via Electrospark Deposition Process: A Feasibility Study

“…is rapid solidification rate, believed to approach 10 5 -10 6°C /s, results in the refinement of the microstructure to either the nanostructured or amorphous level [23]. e solidification mode of the deposited alloy, as well as the resulting grain morphology, is controlled mainly by the thermal condition that exists at the beginning of the solidification.…”

“…Moreover, the reduction of residual stress and distortion compared to the other fusion processes renders this technique highly applicable to those materials possessing a high tendency to crack during welding, such as superalloys, MCrAlY, and thermally sensitive materials (2000 series aluminum alloy) [22][23][24].…”

“…During the process, the electrical arc is pulsed with a frequency varying between 0.1 and 4 KHz using a highfrequency power supply [22,23].…”