Microstructure study on electro discharge deposited magnesium alloy with semi sintered and sintered electrode

Journal of the Mechanical Behavior of Materials

2020

In this study, an endeavour have been made to depositing the electrode materials over the surface of the magnesium alloy using electrical discharge machining (EDM) with WC-Cu powder compacted sintered electrode. Various process parameters such as compaction load, discharge current and pulse on time are selected to carry out the experiment in order to attain the maximum material migration rate (MMR) or deposition rate and microhardness (MH). It was concluded that the MMR and MH increased with increase in discharge current and pulse on time at low compacted electrode but it is decreased at lower discharge current and pulse on time. Highest MMR and MH were attained successfully at partial sintered low compaction load electrode. Microstructure evaluation has been carried out on deposited surface using scanning electron microscopy (SEM) and presence of electrode element in the deposited surface was confirmed by energy dispersive spectroscopy (EDS). Defects mechanism such as globules and craters are formed during EDC with high current and pulse on time respectively, which diminishes the surface roughness. It was observed that the compaction load is the influence parameter on the MMR and MH.

Section: Introductionmentioning

confidence: 99%

Effect of sintered electrode on microhardness and microstructure in electro discharge deposition of magnesium alloy

Elaiyarasan

Journal of the Mechanical Behavior of Materials

2020

“…As pulse on time increase, the DR and EWR increase. At high pulse on time, the diameter of the plasma channel is very large, therefore the produced plasma channel crumbles the large amount materials from the electrode and deposited on the surface, which is confirmed by the Elaiyarasan et al [12]. At low pulse on time, the migration of the electrode material is very low because of low discharge energy, which is not sufficient to melt and vaporize the electrode materials and it was resulted that the small quantity of electrode material transferred on the surface [13].…”

Section: Mathematical Modeling Of Dr and Ewrmentioning

confidence: 67%

Parametric effect on electrical discharge treatment of magnesium alloy with powder composite electrode

Elaiyarasan

2020

SN Appl. Sci.

In this present investigation, an attempt has been made to deposit the composite coating on ZE41A magnesium alloy using tungsten carbide and Nickel powder metallurgy electrode by electro discharge deposition. The experiment is conducted using ordinary EDM and EDM oil as dielectric fluid. Compaction load, current and pulse on time are selected as the input parameters that influences the characteristics such as deposition rate (DR) and electrode wear rate (EWR). Micro hardness of the deposited is evaluated using vicker hardness tester. Mathematical models are developed to study the effect of process parameters on the responses. It is revealed that the DR and EWR increases with increase in current and pulse on time at low compaction load, but it decreases at high compaction load. Maximum DR and EWR are achieved at compaction load (150 MPa), current (4 A) and pulse on time (90 µs). Maximum hardness values (772 HV) is achieved at surface deposited with low compaction and high current and pulse on time. Scanning electron microscope and Energy dispersive spectroscope are carried out in the deposited workpiece to study microstructural and confirm the presence of electrode materials respectively.

“…In this condition, small sized craters (figure 12) were formed in the surface coated at 90 μs. At low pulse on time (50 μs), the diameter of the plasma channel is small that crumbles tiny quantity of material from electrode and migrated on the surface [21]. The deposited surface consists of higher amount of carbon content and excessive formation of other carbides with formation large size globules (figure 13) that affects the surface.…”

Section: Effect Of Process Parameters On Mmr Lt and Mhmentioning

confidence: 99%

Effect of parameters on microstructure of electrical discharge coated ZE41A magnesium alloy with tungsten carbide-copper composite electrode

Elaiyarasan¹,

Surf. Topogr.: Metrol. Prop.

2021

Self Cite

Electrical discharge coating is a material transfer process of EDM used for fabricating composite coating on the workpiece surface. It is applied in the several applications such as surface texturing, die and mould making industries in order to increase the wear and corrosion resistance. In this investigation, ZE41A magnesium alloy is coated with tungsten carbide- Copper (WC-Cu) powder metallurgy electrode. Electrodes are prepared under three different load conditions (150, 175 and 200 MPa). Effects of process parameters on microstructure of the coated surfaces are studied. EDC experiment is carried out by varying the process parameters viz. compaction load (CL), current (I) and pulse on time (Ton). Response characteristics considered in this study are material migration rate (MMR), layer thickness (LT) and micro hardness (MH). MMR, LT and MH increases with increase in current and pulse on time at low compaction loaded electrode. Conversely, it is decreased with low current and pulse on time at high compaction loaded. Average micro hardness of the deposited surface was 125 HV and average layer thickness was 91.6 μm. Different surface defects were identified in the deposited surface such as cracks, craters and globules. Bigger craters were observed at surface deposited with higher current (4 A) that reduced the hardness of the surface.