Microstructure Evolution and Wear Resistance of Cu-Bearing Carbidic Austempered Ductile Iron after Austempering

When the ductile iron which is also known as Spheroidal Graphite (SG) iron, is subjected to austempering heat treatment, the material is known as austempered ductile iron (ADI). This material has good mechanical properties and has various applications in different fields. This revolutionary material with its excellent combination of strength, ductility, toughness and wear resistance has the potential to replace some of the commonly used conventional materials such as steel, aluminium and other light weight alloys as it offers production advantage as well. One of the problems encountered during manufacturing is machining of ADI parts owing to its high hardness and wear resistance. Many researchers over a period of time have reported the machinability aspects of the ADI. This paper presents a review on the developments made on the machinability aspects of ADI along with other mechanical properties.

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Advances in Carbidic Austempered Ductile Iron (CADI) – a wear resistant material

Current Materials Science ◽

10.2174/2666145414666210423125555 ◽

2021 ◽

Vol 14 ◽

Author(s):

Lakshmiprasad Maddi ◽

Ajay Likhite

Keyword(s):

Heat Treatment ◽

Wear Resistance ◽

Cast Iron ◽

Ductile Iron ◽

Viable Alternative ◽

Austempered Ductile Iron ◽

Resistant Material ◽

Fine Carbide ◽

Matrix Graphite ◽

Malleable Cast

Background: Ductile irons provide a more viable alternative for malleable cast iron in areas that do not demand extreme wear resistance. Austempering of ductile irons was a well researched area in the last two decades. Attempts to further improve the wear resistance led to the development of Carbidic austempered ductile iron (CADI), wherein the carbides contribute to wear resistance. Combination of ausferritic matrix, graphite nodules, and carbides (eutectic and alloy) symbolizes the microstructure of CADI. Methods: Two principal approaches adopted by the researchers to change the microstructure are (i) addition of carbide forming elements (ii) heat treatment (s). Results: Both the above methods result in the refinement of graphite nodules, carbide precipitations, along with fine ausferrite. Conclusion: Improvement in hardness, toughness and wear resistance was observed largely as a consequence of fine carbide precipitations and formation of martensite.

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Abrasive Wear Behavior of Permanent Moulded Toughened Austempered Ductile Iron

ASME/STLE 2009 International Joint Tribology Conference ◽

10.1115/ijtc2009-15185 ◽

2009 ◽

Author(s):

T. R. Uma ◽

J. B. Simha ◽

K. Narasimha Murthy

Keyword(s):

Wear Resistance ◽

Abrasive Wear ◽

Ductile Iron ◽

Wear Behavior ◽

Structural Features ◽

Abrasive Wear Resistance ◽

Austempered Ductile Iron ◽

Graphite Morphology ◽

Abrasive Wear Behavior ◽

Austempering Temperature

Laboratory abrasive wear tests have been reported on permanent moulded toughened austempered ductile iron. The influence of austempering temperature on the abrasive wear behavior have been studied and discussed. The results indicate that with increase in austempering temperature from 300°C to 350°C, the abrasive wear resistance increased, and as the austempering temperature increased to 400°C, there was reduction in the abrasive wear resistance. These results have been interpreted based on the structural features and graphite morphology.

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Development of Carbidic Austempered Ductile Iron (CADI)

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.835.163 ◽

2020 ◽

Vol 835 ◽

pp. 163-170

Author(s):

Hayam A. Aly ◽

Adel Nofal ◽

Abdel Hamid A. Hussein ◽

Elsayed M. El-Banna

Keyword(s):

Wear Resistance ◽

Impact Toughness ◽

Ductile Iron ◽

Abrasion Resistance ◽

Austempered Ductile Iron ◽

Image Analyzer ◽

X Ray Diffraction ◽

Individual Factor ◽

Tempering Temperature ◽

Combined Action

This study aimed at optimizing impact toughness and high wear resistant carbidic austempered ductile iron (CADI) by controlling the morphology, size and quantity of carbides. The effects of dynamic solidification, niobium addition, combined action of them and heat treatment have been investigated. Investigations were performed by means of the image analyzer, scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS) and X-ray diffraction. Impact toughness, hardness and abrasion wear resistance tests were conducted. Fracture surfaces were studied. Results indicated that microstructural control during solidification is the most valuable tool to attain the optimum combination between impact toughness and wear resistance in CADI. Combined action of Nb addition and dynamic solidification improves impact toughness, hardness and wear resistance even more than the action of each individual factor. In the as-cast condition, impact toughness, hardness and abrasion resistance were improved after dynamic solidification compared to statically solidify one by 31.2%, 18.75% and 87.96% respectively. This enhancement was increased to 36.9%, 25.93% and 128. % by adding 1% Nb. Lower tempering temperature of 275°C exhibit best hardness and abrasion resistance better than higher tempering temperature of 375°C.

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