N. Parvini Ahmadi
Department of materials Engineering, Sahand University of Technology, Tabriz, Iran
[ 1 ] - Investigation of Transformation Induced Plasticity in High Al–low Si TRIP Steel
This study was conducted in order to investigate the influence of plastic deformation on the transformation of retained austenite in a TRIP steel with a high content of Al and a low content of Si. To the aim, appropriate treatments were used to produce the starting material (TRIP steel). The microstructure of the obtained steel was composed of bainite and phases including ferrite and retained a...
[ 2 ] - An investigation on the passivation behavior of nitrogen enriched AISI 316L austenitic stainless steel
In the present work the effects of plasma nitridization on the passivation behavior of AISI 316L was investigated. To do this; nitriding treatments were carried out at 420°C for 1, 2, 4 and 16 hours. The phase composition and structure of the nitrided layer were studied by Low Angle X-ray diffraction and Scanning Electron Microscopy. The hardness of samples also was evaluated by Vickers microha...
[ 3 ] - Effect of Aluminum on Microstructure and Thickness of Galvanized Layers on Low Carbon silicon-Free Steel
In hot dip galvanizing, several parameters such as chemical composition of coating bath, immersion time and surface roughness of specimens could affect microstructure and properties of coating. In this article, the effect of aluminum content, immersion time and surface roughness on structure and properties of alloy layers have been investigated. Specimens of low carbon silicon-free steel with d...
[ 4 ] - A Study of the Chemical Composition and Heat Treatment of Electroless Ni-B-Tl Alloy Coating on AISI 316 Stainless Steel
Despite having some useful properties, stainless steels suffer from lack of suitable surface hardness. In this research electroless Ni-B-Tl coating was used with the aim to increase their surface hardness. The effects of Nickel chloride, Sodium borohydride, Thallium nitrate and Ethylendiamin on the chemical composition of coating were studied. To achieve an increase in hardness, the effects of ...
[ 5 ] - Some Consideration on Double Layer Structure in Plasma Assisted Nitriding of Austenitic Stainless Steel
Low temperature plasma assisted nit riding treatments of 316 stainless steel produce a complex layer constituted by tow different metastable f.c.c. solid solution denoted ( γ N1 and γ N2 ). About the formation of these double layers, different hypothesis was proposed in the literature. For verifying these hypotheses, the effects of differentes conditions such as nit riding temperature, cleaning...
[ 6 ] - ایجاد پوشش آلیاژی بدون برق Ni-B-Tlو مطالعه برخی از ویژگیهای پوشش ایجاد شده
In this research some properties of an electro less Ni-B-Tl coating (in chloride solution) on AISI 316 grade stainless steel was investigated. An alkaline bath having borohydride sodium as the reducing agent and thallium nitrate as the stabilizer was used to prepare the electroless Ni-B-Ti coating. Variations in micro hardness, deposition rate and weight percentage of the elements Ni, B and Tl ...
[ 7 ] - Synthesis of Nanostructure Ti-45Al-5Cr Alloy by Mechanical Alloying and Study the Effect of Cr Addition on Microstructure of TiAl Alloy
In this work, mechanical alloying was employed to produce Ti-50Al and Ti-45Al-5Cr (at%) alloys. Alloying was performed in a planetary mill and the alloying time varying from 5 to 70h. Characterization of the powder mixture was performed by X-ray diffraction (XRD), SEM analyses and DTA test, during mechanical alloying and after annealing at 1100°c in vacuum oven. The results showed, after 50h of...
[ 8 ] - The Influence Of Process Control Agent (P.C.A)’S State on Expedition of Mechanical Alloying of Anostructure Tial(Γ) Alloy
In this research, the effect of two process control agent: methanol (liquid state) and stearicacid (solid state) on mechanical alloying process of Ti and Al with equal at%(Ti50Al50) wereinvestigated. Phase transformation at presence of two PCA was: at first, powder mixture wastransformed to a metastable solid solution of Al in Ti lattice (disordered hcp) and then transformed toamorphous phase w...
[ 9 ] - Studying the Effect of Productive Factors on Synthesis of Anostructure Tial (Γ) Alloy By Mechanical Alloying
In this research, the Planetary mill was used for mechanical alloying (MA) of Ti and Alpowder mixture with equal at% (Ti50Al50). The effect of various factors, such as process control agent(PCA), speed of rotation of vial and ball-to-powder weight ratio, on process were studied and the bestcondition to synthesis the alloy was determined. Study on X-ray diffraction (XRD) patterns showedthat at p...
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