An improvement of mechanical properties of ductile iron and niobium alloyed ductile iron through new heat treatment cycles / Bulan Abdullah

This research is focused three different heat treatments and they are austempering, tempering and a new heat treatment cycle of ductile iron and niobium alloyed ductile iron. The selection of all heat treatment parameters were based on TTT and CCT diagram which were simulated by JMart Pro Software....

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Main Author: Abdullah, Bulan
Format: Thesis
Language:English
Published: 2011
Subjects:
Online Access:https://ir.uitm.edu.my/id/eprint/7806/1/7806.pdf
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spelling my-uitm-ir.78062023-08-09T08:28:36Z An improvement of mechanical properties of ductile iron and niobium alloyed ductile iron through new heat treatment cycles / Bulan Abdullah 2011 Abdullah, Bulan TJ Mechanical engineering and machinery Metallurgy This research is focused three different heat treatments and they are austempering, tempering and a new heat treatment cycle of ductile iron and niobium alloyed ductile iron. The selection of all heat treatment parameters were based on TTT and CCT diagram which were simulated by JMart Pro Software. The microstructures were observed after etching with 2% Nital using light microscopy and Scanning Electron Microscope (SEM). The structures were verified by XRD analyses. The physical and mechanical tests were then evaluated through density measurement, Rockwell hardness (ASTM El8), Tensile (TS EN 10001-01) and Charpy impact (ASTM E23) tests. The fracture surfaces after tensile test and impact test samples were examined using Scanning Electron Microscope (SEM). The results showed improvement of 60% on tensile strength and 84% on impact toughness with addition of niobium into ductile iron. Superior mechanical properties were obtained after the new heat treatment cycle compared to austempering and tempering processes. This is due to the formation of fine ferrite platelets and lower bainitic structures and dimple rupture fractograph. It was also found that the tensile strength and impact toughness of austempered and tempered samples decreased with respect to longer holding times and higher heat treatment temperature. The development of the new heat treatment cycle in this research is successful in producing high strength materials. This treatment can easily be utilised in heat treatment industry compared with austempering process which required a special salt bath as quenching media. 2011 Thesis https://ir.uitm.edu.my/id/eprint/7806/ https://ir.uitm.edu.my/id/eprint/7806/1/7806.pdf text en public phd doctoral Universiti Teknologi MARA Perpustakaan Tun Abdul Razak Jaffar, Ahmed
institution Universiti Teknologi MARA
collection UiTM Institutional Repository
language English
advisor Jaffar, Ahmed
topic TJ Mechanical engineering and machinery
Metallurgy
spellingShingle TJ Mechanical engineering and machinery
Metallurgy
Abdullah, Bulan
An improvement of mechanical properties of ductile iron and niobium alloyed ductile iron through new heat treatment cycles / Bulan Abdullah
description This research is focused three different heat treatments and they are austempering, tempering and a new heat treatment cycle of ductile iron and niobium alloyed ductile iron. The selection of all heat treatment parameters were based on TTT and CCT diagram which were simulated by JMart Pro Software. The microstructures were observed after etching with 2% Nital using light microscopy and Scanning Electron Microscope (SEM). The structures were verified by XRD analyses. The physical and mechanical tests were then evaluated through density measurement, Rockwell hardness (ASTM El8), Tensile (TS EN 10001-01) and Charpy impact (ASTM E23) tests. The fracture surfaces after tensile test and impact test samples were examined using Scanning Electron Microscope (SEM). The results showed improvement of 60% on tensile strength and 84% on impact toughness with addition of niobium into ductile iron. Superior mechanical properties were obtained after the new heat treatment cycle compared to austempering and tempering processes. This is due to the formation of fine ferrite platelets and lower bainitic structures and dimple rupture fractograph. It was also found that the tensile strength and impact toughness of austempered and tempered samples decreased with respect to longer holding times and higher heat treatment temperature. The development of the new heat treatment cycle in this research is successful in producing high strength materials. This treatment can easily be utilised in heat treatment industry compared with austempering process which required a special salt bath as quenching media.
format Thesis
qualification_name Doctor of Philosophy (PhD.)
qualification_level Doctorate
author Abdullah, Bulan
author_facet Abdullah, Bulan
author_sort Abdullah, Bulan
title An improvement of mechanical properties of ductile iron and niobium alloyed ductile iron through new heat treatment cycles / Bulan Abdullah
title_short An improvement of mechanical properties of ductile iron and niobium alloyed ductile iron through new heat treatment cycles / Bulan Abdullah
title_full An improvement of mechanical properties of ductile iron and niobium alloyed ductile iron through new heat treatment cycles / Bulan Abdullah
title_fullStr An improvement of mechanical properties of ductile iron and niobium alloyed ductile iron through new heat treatment cycles / Bulan Abdullah
title_full_unstemmed An improvement of mechanical properties of ductile iron and niobium alloyed ductile iron through new heat treatment cycles / Bulan Abdullah
title_sort improvement of mechanical properties of ductile iron and niobium alloyed ductile iron through new heat treatment cycles / bulan abdullah
granting_institution Universiti Teknologi MARA
granting_department Perpustakaan Tun Abdul Razak
publishDate 2011
url https://ir.uitm.edu.my/id/eprint/7806/1/7806.pdf
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