The synergistic action and interplay of hydrogen embrittlement mechanisms in steels and iron: Localized plasticity and decohesion

Influence of hydrogen-enhanced plasticity and decohesion mechanisms of hydrogen embrittlement on the fracture resistance of steel

Dual role of nanosized NbC precipitates in hydrogen embrittlement susceptibility of lath martensitic steel

Tensile mechanical properties and fracture behaviors of nickel-based superalloy 718 in the presence of hydrogen

Microstructural and crystallographic study of hydrogen-assisted cracking in high strength PSB1080 steel

Electrochemical discharge machining has been proved to be efficient micro-machining process and significantly used for the machining of non-conductive materials. The miniaturized products have gain...

Electrochemical discharge machining: A review on preceding and perspective research:

Slow strain rate tensile (SSRT) tests were performed on tempered 13 wt% Cr martensitic stainless steel (MSS) with hydrogen charging during straining and also separately on hydrogen pre-charged tensile specimens. Microstructural characterization of tempered MSS showed lath martensitic structure with sub-micron sized M 23 C 6 type carbides at lath interfaces and high angle grain boundaries. There was no change in the yield strength but loss in ductility was observed with increase of absorbed hydrogen quantity/pre-charging duration. Fracture surface examination showed increased brittle (intergranular) zone with increase of absorbed hydrogen. Compared to hydrogen pre-charging, effect of hydrogen charging during straining was more pronounced on the mechanical properties as both ductility and yield strength decreased. A change in the fracture mode form ductile dimples to mixed and intergranular fracture was observed with the increase of cathodic current density. Hydrogen enhanced decohesion embrittlement (HEDE) is the dominant mechanism for hydrogen pre-charged and also with hydrogen charging during straining conditions.

Influence of hydrogen on mechanical properties and fracture of tempered 13 wt% Cr martensitic stainless steel

Electrochemical discharge machining (ECDM) is a versatile machining process due to its applicability to machine different materials regardless to their properties. In this work, machining behaviour of silicon wafer using ECDM is presented. An attempt has been made to drill micro holes on silicon wafer considering applied voltage and tool feed rate as input process parameters. The overcut and hole taper were observed as output quality characteristics. The experimental results revealed that overcut and hole taper increase with increase in voltage and decreases with increase in tool feed rate. The characterization of micro holes has been carried out using scanning electron microscopy and revealed the presence of small debris, overcut and heat affected zone on machined surface. Overall, it was observed that micro hole machined at conditions i.e. applied voltage 60 V, tool feed rate 250 μm/min results in minimum overcut and hole taper. The axial, lateral and flank erosion was observed on the micro tool used for machining of silicon wafer.

Experimental Investigation for Generation of Micro-Holes on Silicon Wafer Using Electrochemical Discharge Machining Process

Investigating the impact of LASER assistance on the accuracy of micro-holes generated in carbon fiber reinforced polymer composite by electrochemical discharge machining

The SiC reinforced z-pinned composites are becoming advantageous in the field of aerospace and defense sector due to their superior mechanical properties. The reinforcement of SiC particles makes them difficult to machine with conventional machining processes. In the present research investigation, the micro-slicing of SiC reinforced z-pinned composites has been attempted using wire electrochemical discharge machining (WECDM). WECDM is newly emerging technique which combines the process features of electrochemical machining (ECM) and wire electrical discharge machining (WEDM) processes. The experiments were planned using Taguchi’s methodology using L9 Orthogonal array to study the effect of various process parameters i.e. applied voltage, wire feed rate (WFR) and duty cycle on the output quality characteristics such as diametric overcut (DOC) and material removal rate (MRR). The grey relational analysis (GRA) methodology was implemented for multi-response optimization. The diametric overcut and material removal rate of machined samples at optimum parametric conditions of GRA method improves from 71.87 μm to 60.20 μm and 34.20 mg/min to 32.30 mg/min respectively. The morphology of micro-sliced sample using GRA method signifies better quality machined surface with minimization of micro-cracks and uniform cutting.

Manpreet Singh

Papers

Electrochemical discharge machining: A review on preceding and perspective research:

Influence of hydrogen on mechanical properties and fracture of tempered 13 wt% Cr martensitic stainless steel

Experimental Investigation for Generation of Micro-Holes on Silicon Wafer Using Electrochemical Discharge Machining Process

Investigating the impact of LASER assistance on the accuracy of micro-holes generated in carbon fiber reinforced polymer composite by electrochemical discharge machining

Wire-Electrochemical Discharge Machining of SiC Reinforced Z-Pinned Polymer Matrix Composite Using Grey Relational Analysis