Corrosion resistance of heat treated Ti6Al4V in NaCl
- Authors: Omoniyi, P.O. , Akinlabi, E.T. , Mahamood, R.M. , Jen, T.C.
- Date: 2021
- Subjects: Corrosion , Heat treatment , Ti6Al4V
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/485969 , uj:44190 , DOI: 10.1016/j.cdc.2021.100780 , Citation: P.O. Omoniyi, E.T. Akinlabi, R.M. Mahamood, T.C. Jen, Corrosion resistance of heat treated Ti6Al4V in NaCl, Chemical Data Collections, Volume 36, 2021, https://doi.org/10.1016/j.cdc.2021.100780.
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Effect of heat treatment on microstructure and mechanical properties of magnesium alloy
- Authors: Sanusi, Kazeem O. , Madushele, Nkosinathi , Akinlabi, Esther Titilayo
- Date: 2018
- Subjects: Magnesium , Heat treatment , Microstructure
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/260614 , uj:27447 , Citation: Sanusi, K.O., Madushele, N. & Akinlabi, E.T. 2018. Effect of heat treatment on microstructure and mechanical properties of magnesium alloy.
- Description: Abstract: In this research study, the effect of heat treatment on mechanical properties, and microstructure characteristics of magnesium alloy with 99.94 % magnesium was studied. The heat treatment of samples was conducted at 150 ⁰C, 300 ⁰C, and 450 ⁰C for 2 hours. The samples were characterized by microstructure characterization using optical microscope (OEM) by observing the evolution of the microstructure of the heat-treated magnesium alloy. The hardness test was done on the surface of each sample using the load of 50 N to show the effect of heat treatment on the cross-section surface of magnesium alloy. From the results, the average grain sizes of the materials are different due to the different heat treatment and cooling rate of the materials.it is found that the hardness of the surface of the samples is higher at the edges of the samples than in the middle. The changes in average hardness of magnesium with the increase in temperature is due to an increase in grain size.
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Effect of rapid cooling of high temperature laser fabricated Ti/B4C/BN coating on Ti-6AL-4V alloy
- Authors: Franklin, Ochonogor O. , Akinlabi, Esther Titilayo , Nyembwe, Kasongo D. , Pityana, Sisa , Shongwe, Mxolisi Brendon
- Date: 2016
- Subjects: Heat treatment , Titanium alloys
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/214859 , uj:21334 , Citation: Franklin, O.O. et al. 2016. Effect of rapid cooling of high temperature laser fabricated Ti/B4C/BN coating on Ti-6AL-4V alloy.
- Description: Abstract: A hybrid Ti-6Al-4V based metal matrix composites characterized of martensitic structure was formed using three hoper system. Different volume percentages used were as follows: 3.0 vol. % of Ti-6Al-4V, 3.2 vol. % of Ti-6Al-4V and 3.4 vol. % of Ti-6Al-4V respectively while an equal amount of BN and B4C mixed with the Ti-6Al-4V powder particle was fed through the hoper systems at a constant laser power 2000 W and scanning speed of 1.0 m/s. The influence of rapid cooling and varied powder particle at constant coating temperature on the surface morphology and hardness property of Ti-6Al- 4V/B4C/BN alloy systems was however investigated. The hardness result of experimental showed a general improvement. Further result showed that the Ti-6Al- 4V/B4C/BN system fabricated at 3.0 Ti Vol. percent had a hardness improvement as high as 986.9 HVO.5 compared to the as receive Ti-6Al-4V substrate Hardness value of about 357.3 HVO.5. 3.2 Ti Vol. percent systems recorded a hardness value of 723.4 HVO.5 and 3.2 Ti Vol. percent system recorded a hardness value of 609.6 HVO.5. Optical microscope (OM) Scanning electron microscope (SEM) was also carried out for microstructural evaluation and Energy Dispersive Spectroscopy (EDS) to confirm the elemental composition of coating when necessary.
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Heat treatment significantly increases the Sharpness of silcrete stone tools
- Authors: Key, A. , Pargeter, J. , Schmidt, P.
- Date: 2021
- Subjects: Heat treatment , Silcrete , Durability
- Language: English
- Type: Journal article
- Identifier: http://hdl.handle.net/10210/490276 , uj:44731 , Citation: Key, A., Pargeter, J. and Schmidt, P., 2021. Heat treatment significantly increases the sharpness of silcrete stone tools. Archaeometry, 63(3), pp.447-466. , DOI : 10.1111/arcm.12619
- Description: Abstract: Humans were regularly heat‐treating stone tool raw materials as early as 130,000 years ago. The late Middle Stone Age (MSA) and Late Stone Age (LSA) of South Africa’s Western Cape region provides some of the earliest and most pervasive archaeological evidence for this behaviour. While archaeologists are beginning to understand the flaking implications of raw material heat treatment, its potential functional benefits remain unanswered. Using silcrete from the Western Cape region, we investigate the impact of heat treatment on stone tool cutting performance. We quantify the sharpness of silcrete in its natural, unheated form, before comparing it with silcrete heated in three different conditions. Results show that heat‐treated silcrete can be significantly sharper than unheated alternatives, with cutting forces halving and energy requirements reducing by approximately two‐thirds. The data suggest that silcrete may have been heat treated during the South African MSA and LSA to increase the sharpness and performance of stone cutting edges. This early example of material engineering has implications for understanding Stone Age populations’ technological capabilities, inventiveness and raw material choices. We predict that heat‐treatment behaviours in other prehistoric and ethnographic contexts may also be linked to increases in edge sharpness and concerns about functional performance.
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Influences of external chlorides and synthetic zeolite on delayed ettringite formation
- Authors: Ekolu, Stephen O.
- Date: 2018
- Subjects: Delayed ettringite formation , Heat treatment , Pessimum
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/279832 , uj:30060 , Citation: Ekolu, S.O. 2018. Influences of external chlorides and synthetic zeolite on delayed ettringite formation.
- Description: Abstract: Investigations were conducted to evaluate the effects of synthetic zeolite additive and sea salt on the potential for delayed ettrintite formation (DEF) in heat cured cementitiuos systems. Mortar prisms 25x25x285 mm were prepared at water-cement ratio (w/c) = 0.5, using CEM I 42.5 N,R. Sulphates were introduced into the mixtures by adding 2%, 3% and 5%SO3. Also, a commercially available synthetic zeolite additive PWC was added to cement at proportions of 1%, 0.5% and 2.5%PWC. The mortar specimen were heat-treated at 95oC then stored in water, seawater or 0.5M, 1.0M, 1.5M and 2.0M NaCl solutions, and monitored for expansion of the prisms over a period of three months...
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XRD investigation on heat treatment of high chrome white cast irons
- Authors: Ngqase, M. , Pan, X.
- Date: 2020
- Subjects: white cast irons , High chrome white cast irons , Heat treatment
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/453538 , uj:40043 , DOI: 10.1088/1742-6596/1495/1/012022 , Citation: M. Ngqase and X. Pan 2020 J. Phys.: Conf. Ser. 1495 012022
- Description: Abstract: The properties of hypoeutectic iron of HCWCI containing 25 wt. %Cr-2.5 wt. %C were investigated after destabilisation heat treatments, cooling (slow and fast cooling) to ambient temperatures, their influence on the structure and hardness was investigated using Xray diffraction (XRD), element distribution analysis and hardness tests. The experimental results show that appropriate heat treatments contribute to a significant improvement on the mechanical properties of selected alloy of HCWCI. The results are discussed in terms of the change in austenite phase at the different destabilisation heat treatment temperatures.
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