SEARCH RESULT

Electro-discharge process (EDM) is an important manufacturing technique for the manufacture of the hard and conductive materials. The goal of this work is to investigate the (EDM) processes using low carbon steel The work involves cutting holes by Electro discharge machine using copper electrode and using Taguchi analysis to obtain the best cut-off parameters. The impact of various parameters such as (current, pulsation on time and pulsation off time) are studied on the surface roughness, material removal rate and macro hardness. Nine samples were run by using CNC-EDM machine which used for mild carbon steel by supplied DC current values (10, 30, 50A), pulse on time (100, 150, 200µs) and pulse off time (4, 12, 25µs) uses to cut 3mm thickness of the steel utilizing the copper electrode.The result from this work is useful to be implemented in industry to reduce the time and cost. It is observed that the applied current has the most influence parameters of surface roughness, material removal rate and macro hardness while pulse on time and plus off time have less influence parameter on it. The maximum Ra, MMR and HV which are achieved was (1.813 µm, 23.523 mm3/min, 173.1), respectively. The qualitative assessment reveals that the MRR, Ra, HV were increases as the applied current increases.

International Iron & Steel Symposium
UDCS

Shukry H. Aghdeab Marwa Qasim Ibraheem Nareen Hafidh Obaeed Ali Abdul Munim Alhattab

This paper aims to investigate the effect of Laser surface melting (LSM) and Mo alloying on plasma transferred arc (PTA) deposited Co-Based Stellite 6 Hardfacings. LSM'ed and Mo alloyed samples were characterized using X-ray diffractometer and scanning electron microscopy. LSM’ed unalloyed Stellite 6 exhibited a microstructure similar to its PTA state in terms of constituent phases but at finer scale as a result of high cooling rate of the melt pool followed the LSM process. Whereas in the LSM’ed Mo-alloyed Stellite 6, only two distinct phases have been observed, whereby the complex carbides appear as interconnected network and the matrix phase appears in fine cellular dendritic morphology. The subsequent LSM process of the unalloyed and Mo-alloyed Stellite 6 led to an increment in the surface hardness as compared to the PTA version. Room temperature wear resistance was examined under testing loads of 1, 2, 3 and 4N and corresponding wear coefficient 'k' was determined. The k values showed that there was almost 25% reduction in wear loss upon the LSM process. This dual approach of Mo alloying and LSM led to a 75% reduction in wear loss than the PTA version.

International Iron & Steel Symposium
UDCS

Ali Abdul Munim Alhattab Shaikh Asad Ali Dilawary Amir Motallebzadeh C. Fahir Arisoy Huseyin Cimenoglu