The Effect of Isothermal Heat Treatment Time on the Microstructure and Properties of 2.11% Al Austempered Ductile Iron

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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Austenitization of FerriticDuctile Iron

Archives of Foundry Engineering ◽

10.2478/afe-2014-0085 ◽

2014 ◽

Vol 14 (4) ◽

pp. 49-54 ◽

Cited By ~ 1

Author(s):

A. Krzyńska ◽

A. Kochański

Keyword(s):

Heat Treatment ◽

Ductile Iron ◽

Starting Material ◽

Austempered Ductile Iron ◽

Isothermal Quenching ◽

Micro Hardness ◽

Hardness Testing ◽

Ferritic Matrix ◽

Rate Of Dissolution ◽

Nodular Graphite

Abstract Austenitization is the first step of heat treatment preceding the isothermal quenching of ductile iron in austempered ductile iron (ADI) manufacturing. Usually, the starting material for the ADI production is ductile iron with more convenient pearlitic matrix. In this paper we present the results of research concerning the austenitizing of ductile iron with ferritic matrix, where all carbon dissolved in austenite must come from graphite nodules. The scope of research includedcarrying out the process of austenitization at 900° Cusing a variable times ranging from 5 to 240minutes,and then observations of the microstructure of the samples after different austenitizing times. These were supplemented with micro-hardness testing. The research showed that the process of saturating austenite with carbon is limited by the rate of dissolution of carbon from nodular graphite precipitates

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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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Low-temperature thermal pretreatment process for recycling inner core of spent lithium iron phosphate batteries

Waste Management & Research ◽

10.1177/0734242x20957403 ◽

2020 ◽

pp. 0734242X2095740

Author(s):

Haijun Bi ◽

Huabing Zhu ◽

Lei Zu ◽

Yong Gao ◽

Song Gao ◽

...

Keyword(s):

Heat Treatment ◽

Low Temperature ◽

Heat Treatment Temperature ◽

Lithium Iron Phosphate ◽

Inner Core ◽

Treatment Time ◽

Iron Phosphate ◽

Treatment Temperature ◽

Heat Treatment Time ◽

Physicochemical Changes

Spent lithium iron phosphate (LFP) batteries contain abundant strategic lithium resources and are thus considered attractive secondary lithium sources. However, these batteries may contaminate the environment because they contain hazardous materials. In this work, a novel process involving low-temperature heat treatment is used as an alternative pretreatment method for recycling spent LFP batteries. When the temperature reaches 300°C, the dissociation effect of the anode material gradually improves with heat treatment time. At the heat treatment time of 120 minutes, an electrode material can be dissociated. The extension of heat treatment time has a minimal effect on quality loss. The physicochemical changes in thermally treated solid cathode and anode materials are examined through scanning electron microscopy with energy-dispersive X-ray spectroscopy. The heat treatment results in the complete separation of the materials from aluminium foil without contamination. The change in heat treatment temperature has a small effect on the quality of LFP material shedding. When the heat treatment temperature reaches 300°C and the time reaches 120 minutes, heat treatment time increases, and the yield of each particle size is stable and basically unchanged. The method can be scaled up and may reduce environmental pollution due to waste LFP batteries.

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