Md. Mohafizul Haque

Study on the Microstructure and Properties of Fe-C-Si and Fe-C-Al Cast Irons

Two types of cast irons with Fe-C-Si and Fe-C-Al. alloy systems were investigated in the present study. In order to modify the microstructure and properties of cast iron, Al was added to low silicon pig iron that is in Fe-C-Al (Sorel metal) alloy system. Its effect was then studied with comparing to normal Fe-C-Si alloy system. Both cast irons were produced in sand mould of suitable design to provide all information regarding the structure and properties. The microstructure was analyzed using optical microscope which showed the distribution of graphite flakes in pearlite or ferro-pearlite matrix. The size of the graphite flakes in Fe-C-Al system was smaller and more evenly distributed compared to the Fe-C-Si alloy system. The cast product was also characterized by using XRD. The maximum hardness of the Fe-C-Al alloy was measured as 110.2 HRB compared to 89.32 HRB of the conventional Fe-C-Si alloy system. The impact test results showed that Fe-C-Al cast iron has higher impact property than Fe-C-Si cast iron.

Wear Characteristics of Fe-C-Si and Fe-C-Al Cast Irons

In order to study the wear properties of Fe-C-Si and Fe-C-Al alloy systems, castings were produced in resin bonded sand mould of suitable design, which provides information regarding various thicknesses of the castings. Gray cast iron is an inexpensive and readily available material used for manufacturing of roller, roller shell, piston rings, cylinder liners, etc. Its low melting point is characterized as unique combination of superior properties like good friction and wear properties and economic in manufacturing. In the present study, wear behavior of the Fe-C-Si and Fe-C-Al cast irons were investigated using a pin-on-disk type apparatus at room temperature. Alumina ball of 3 mm diameter was used as pin, while the cast sample served as the disk. The tests were carried out at a normal load of 5.0 N and a sliding velocity of 250 mm/s for 30 min. The Fe-C-Al cast iron showed a wear rate of 3.3203×10-5 mm3/m/N compared to 12.42×10-5 mm3/m/N of Fe-C-Si cast iron. The worn surfaces were analyzed using optical profilometer and SEM.

Investigation on tool wear rate for modified and unmodified aluminium-silicon casting alloy

This study demonstrates and explains the effect of strontium modification on machinability of aluminium-silicon eutectic (LM-6 type) alloy. This alloy is known to have many favourable features including weight to strength ratio, high corrosion resistance and excellent castability. However, normal unmodified LM-6 alloy has poor machinability, which reduces its applications range. In this work, various samples of LM-6 alloy were cast using sand and metallic chill mould with and without strontium addition. Machining on each cast product, was carried out using recommended cutting parameters for Al-Si alloys. Strontium modified samples have recorded a reduction in average flank wear, an increase in shear plane angles and a reduction in chip thickness. The main reason for this improvement is the refining effect of strontium, which reduces the size of the hard silicon particles. As a result, their abrasive action on the tool face has reduced a lot. Dramatic reductions in tool wear rate were recorded when the microstructures were refined. On the other hand, when no refinement of microstructure occurs, tool wear rate becomes high. Chip analysis showed that strontium modified sample produced a thinner chip thickness with a larger shear plane angle, requiring less cutting forces. The tool wear depends not only on the phases present in the work material, but also on their sizes and distribution over entire structure. Thus, strontium modification has better effect on machinability of die cast alloy compared to that of the sand cast LM-6 alloy.

Engineering Materials and Manufacturing Processes from Qur’anic Perspective

Any useful object is commonly made from selected engineering materials with proper shape and dimension. The selection of materials and manufacturing processes is an important criterion towards the production of useable and affordable objects. The technologies behind this knowledge are needed to acquire through study, proper education, practical training and scientific research related to Materials and Manufacturing Engineering (MME). Allah (swt), the sources of all power and knowledge, has bestowed the Guide Book, the Holy Qur’an through His beloved Messenger Prophet Mohammad (pbuh) to the mankind. Allah (swt) narrated various stories in many Surahs of the noble Qur’an related to applied science and technology. This paper is an attempt to view the integration between the revealed knowledge and the science and technology based knowledge related to engineering materials and manufacturing processes. Finally, stresses have been given to acquire knowledge on science and technology based education and understanding, and disseminate it for the cause of humanity.