Development of carbide intermetallic layer by electric discharge alloying on AISI-D2 tool steel and its wear resistance

Abstract

Electrical discharge alloying was performed on AISI-D2 steel using Ni-Wp owder mixed dielectrici no rder to improve the hardness and to reduce the specific wear rate. The alloyed layer was characterized using optical microscopy,s canning electron microscopy, X-ray diffraction analysis and energy-dispersive spectroscopy. Wear tests were conducted based on L9 orthogonalarray in apin-ondisc tribometer and the alloying parameters were optimized using Taguchi's technique. Hard intermetallics based on Fe 7 C 3 ,C r 3 C 2 and Ni 2 W 4 Cw ere formed by electric discharge alloying, which primarilyc ontributed to the improvementi nh ardness up to 600 HV 0.5 .T he specific wear rate of the alloyed layer was subsequently reduced by around afactor of eightcompared to that of the base material. The pulse off-time was found to be predominant in obtaining higher hardness and lower specific wear rate among the alloyingp arameters, peak current, pulse on-time and off-time.

Micro-structure and self-lubricant properties of powder mixed electrical discharge metal matrix composite coating

“…Formation of such carbides together with alloying elements, possess higher hardness value compare with deposition of pyrolysis carbon settled on the substrate materials. 22,23 Coating layer thickness are depending on factors like powder concentration, electrical conductivity, density and machining parameter particularly current.…”

Modelling and Analysis of Electrical Discharge Alloying through Taguchi Technique

“…Several trials were conducted on a semi-automatic die-sinking EDM machine energized by a 35-Ampere current pulse generator with reverse polarity in order to find the range of parameters, within which the samples could be alloyed. The alloying time was set to be 15 minutes with intermediate stirring to avoid settlement of powder the experimental procedure is described else were [5]. An L 27 orthogonal array was used for the design of experiments and the different parameter combinations were as obtained in Table [2].The process parameters and the alloying condition are in Table 3ALT was measured using optical microscope.…”

Synthesis of alloying Al 7075 with Molybdenum for Functional Characterization

“…A 200 mm long copper rod as anode has been used as a negative terminal. This strategy was used with a hydrocarbon dielectric medium mixed with Mo powder (50 gm) of 10 to 20 micron atom gage and the blending of Mo powders in the work tank will stop the channel between the essential tank and the work tank, which normally channels the debris surrounded in the middle of the machining [20][21]. To outscore this problem, an exclusively designed machining tank with a flouting point of 10 liters was used for the examination as shown in Fig 2.…”