Papers by Author: Said Mechachti

Abstract: The objective of this work is the development of a Fe-W-Ni sintered steel obtained by the powder metallurgy technique. The latter is widely used today for the design of new alloys based on powders (iron) to meet industrial requirements in strength and wear characteristics. The proposed alloy is based on iron mixed with 5% nickel and various percentages (5, 10, 15 and 20%) of tungsten. The effect of the tungsten W content on mechanical and structural properties is presented.

Abstract: Powder metallurgy was mainly used to produce automobile parts such as beds self-lubricating bearings, and gear wheels. In order to investigate the effect of porosity on the mechanical and tribological properties of sintered steel, specimens with 10%, 20%, and 30% porosity were produced on samples of parallelepipedic form, with technical of iron powders that has been used in a large industrial area. Sintering was carried out at 1100 ° C for 2 hours in an argon atmosphere. Metallographic studies such as pore formation, saturated area, and the nitrided layer analyses were performed by microscopy and optical microscopy. It was found that the irregular pore formation tendencies increase with an increase in porosity (%). Furthermore, an increase in porosity has proven to decrease the mechanical properties and increase the wear trace area and the friction coefficient of sintered steel.

Abstract: The present work aims at determining the effects of Nickel addition on the phase’s distribution in sintered part. It aims equally at identifying the effect of such addition on the microstructure and the mechanical properties. The addition to mixtures of alloying elements in their primitive form can lead to the formation of a heterogeneous microstructure in the sintered parts produced by the powder metallurgy (PM) process. It has been proved that the addition of nickel to an iron powder mixture forms nickel-rich areas (NRA) in the sintered parts. This is basically related to the low diffusion rate of nickel in iron at conventional sintering temperatures.