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Professor Yong Sun

Job: Professor

Faculty: Computing, Engineering and Media

School/department: School of Engineering and Sustainable Development

Research group(s): Solid Mechanics and Materials Research Group, Institute of Engineering Sciences

Address: De Montfort University, The Gateway, Leicester, LE1 9BH, United Kingdom

T: +44 (0)116 257 7072

E: ysun01@dmu.ac.uk

W: https://www.dmu.ac.uk

 

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Research group affiliations

Solid Mechanics and Materials Research Group (Leader)

Institute of Engineering Sciences (IES)

Publications and outputs

  • Self-Reinforced Composite Materials: Frictional Analysis and Its Implications for Prosthetic Socket Design
    dc.title: Self-Reinforced Composite Materials: Frictional Analysis and Its Implications for Prosthetic Socket Design dc.contributor.author: Nagarajan, Yogeshvaran R.; Hewavidana, Yasasween; Demirci, Emrah; Sun, Yong; Farukh, Farukh; Kandan, Karthikeyan dc.description.abstract: Friction and wear characteristics play a critical role in the functionality and durability of prosthetic sockets, which are essential components in lower-limb prostheses. Traditionally, these sockets are manufactured from bulk polymers or composite materials reinforced with advanced carbon, glass, and Kevlar fibres. However, issues of accessibility, affordability, and sustainability remain, particularly in less-resourced regions. This study investigates the potential of self-reinforced polymer composites (SRPCs), including poly-lactic acid (PLA), polyethylene terephthalate (PET), glass fibre (GF), and carbon fibre (CF), as sustainable alternatives for socket manufacturing. The tribological behaviour of these self-reinforced polymers (SrPs) was evaluated through experimental friction tests, comparing their performance to commonly used materials like high-density polyethylene (HDPE) and polypropylene (PP). Under varying loads and rotational speeds, HDPE and PP exhibited lower coefficients of friction (COF) compared to SrPLA, SrPET, SrGF, and SrCF. SrPLA recorded the highest average COF of 0.45 at 5 N and 240 rpm, while SrPET demonstrated the lowest COF of 0.15 under the same conditions. Microscopic analysis revealed significant variations in wear depth, with SrPLA showing the most profound wear, followed by SrCF, SrGF, and SrPET. In all cases, debris from the reinforcement adhered to the steel ball surface, influencing the COF. While these findings are based on friction tests against steel, they provide valuable insights into the durability and wear resistance of SRPCs, a crucial consideration for socket applications. This study highlights the importance of tribological analysis for optimising prosthetic socket design, contributing to enhanced functionality and comfort for amputees. Further research, including friction testing with skin-contact scenarios, is necessary to fully understand the implications of these materials in real-world prosthetic applications. dc.description: open access article
  • Laser Surface Engineering for Tribology
    dc.title: Laser Surface Engineering for Tribology dc.contributor.author: Ji, Xiulin; Sun, Yong dc.description.abstract: This book is a reprint of the Special Issue Laser Surface Engineering for Tribology that was published in Lubricants dc.description: Tribology grapples with diverse challenges, seeking to minimize friction and wear, and to advance the energy efficiency and sustainability of machinery. Laser surface engineering emerges as a highly effective solution with which to tackle these challenges. Recent advancements in this field, including techniques like laser texture, laser deposition, laser cladding, and laser modification, have found widespread applications in tribology. Surface-strengthening coatings, prepared via laser manufacturing, stand out as one of the most efficient strategies to mitigate tribological issues. The laser processing-related techniques either alter the surface texture or create a new film, thereby enhancing the mechanical, physical, and chemical properties of the contact surfaces. These innovations have seamlessly integrated into various industrial applications. This comprehensive reprint encompasses surface texturing, laser processing, and post-machining. Various metals, such as cast iron, steel, high-entropy alloy, and Ti-based, Cu-based, Al-based, and Ni-based alloys, are explored in this reprint, with a dedicated focus on leveraging laser surface engineering for tribological enhancements. In the pursuit of ongoing advancements in this field, contributors participate in this reprint, encompassing the domains of laser surface engineering and tribology, in order to delve into and share their insights. We anticipate that this reprint will draw attention to key research trends and state-of-the-art developments in laser surface engineering for tribology.
  • Special issue on Laser surface engineering for tribology
    dc.title: Special issue on Laser surface engineering for tribology dc.contributor.author: Ji, Xiulin; Sun, Yong dc.description.abstract: This Special Issue compiles significant contributions addressing challenges in laser surface engineering for tribology, suggesting a future research focus on application-specific optimization. This involves tailoring laser surface engineering approaches to meet the diverse requirements of various industries, including automotive, aerospace, and manufacturing. Additionally, the utilization of advanced characterization techniques like in situ microscopy and spectroscopy is advantageous for a deeper understanding of dynamic changes in laser-modified surfaces during tribological testing. These proposed research directions aim to further advance laser surface engineering for tribological applications, tackling current challenges and enhancing the practical implementation of these techniques. dc.description: open access article
  • Corrosive-wear performance of grade 316 stainless steel sliding against grade 316 stainless steel in NaCl solution
    dc.title: Corrosive-wear performance of grade 316 stainless steel sliding against grade 316 stainless steel in NaCl solution dc.contributor.author: Bailey, Richard; Sun, Yong dc.description.abstract: Most of the reported corrosive-wear or tribocorrosion tests have been carried out using an inert and insulating counter-body in the experimental set up, with the purpose of eliminating the direct contribution of the counter-body to the electrochemical response during sliding wear. Little work has been reported using the same material as the test specimen and as the counter-body. In this work, corrosive-wear experiments have been carried out on the same material contact, i.e., stainless steel on stainless steel (SS-SS), where a 316 SS specimen was sliding against a 316 SS slider in 0.5 M NaCl solution under controlled electrochemical conditions. For comparison purpose, similar experiments have also been conducted on the 316 SS-Al2O3 sliding pair. The tests were conducted under reciprocating sliding conditions at 1 Hz frequency, 4 N load and for a duration of 7200 s, incorporated with electrochemical control which included potentiodynamic polarization and potentiostatic polarization at constant negative and positive potentials with respect to the open circuit potential (OCP). The results show that the counter-body has a large effect on the corrosive-wear behaviour of the 316 SS specimen under all test conditions. As compared to the SS-Al2O3 sliding pair, the SS-SS pair experiences larger material removal from the specimen. Adhesive wear occurs in the SS-SS pair which leads to significantly roughened sliding surfaces and unstable frictional behavior and electrochemical response. Further analysis revealed that mechanical wear plays a more dominant role in material removal in the SS-SS pair than in the SS-Al2O3 pair, and it is the corrosion-accelerated wear that contributes to the significantly increased material removal in the SS-SS pair. dc.description: The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.
  • Effect of thermal oxidation on the dry sliding friction and wear behaviour of CP‑Ti on CP‑Ti tribopairs
    dc.title: Effect of thermal oxidation on the dry sliding friction and wear behaviour of CP‑Ti on CP‑Ti tribopairs dc.contributor.author: Sun, Yong; Bailey, Richard; Zhang, Jin; Lian, Yong; Ji, Xiulin dc.description.abstract: Thermal oxidation (TO) has proven to be a cost-effective and efficient technique to engineer the surfaces of titanium and its alloys to achieve enhanced surface properties. The benefits of TO treatment in enhancing the tribological properties of titanium have been demonstrated by many investigators. However, most of the reported tribological studies have been based on the contact between a TO treated titanium specimen and a counter-body made of other materials, mainly ceramics, steels and polymers. Very few studies have been reported on the friction and wear behaviour of TO treated titanium sliding against TO treated titanium. In this work, the effect of thermal oxidation on the dry sliding friction and wear behaviour of commercially pure Ti (CP-Ti) on CP-Ti tribopairs was investigated under loading conditions ranging from elastic contact to plastic contact. Comparisons were made among three contact pairs: (1) untreated Ti on untreated Ti (Ti–Ti), (2) untreated Ti on TO treated Ti (Ti-TO) and (3) TO treated Ti on TO treated Ti (TO-TO). The results show that the TO-TO contact pair presents an ideal material combination to achieve the best tribological performance in terms of low friction and superior wear resistance. On the other hand, the Ti–Ti pair presents the worst combination in terms of tribological performance. While the Ti-TO pair performs better than the Ti– Ti pair tribologically, it is not as good as the TO-TO pair. It is essential to thermally oxidize both specimens in order to achieve optimal tribological performance. It is the oxide layer-on-oxide layer contact that imparts the excellent tribological performance. Failure of the oxide layer in one of the contact bodies can lead to high and unstable friction and increased wear from both contacting bodies. The tribological performance of the three contact pairs and the failure mechanism of the oxide layer are discussed in the paper. The results of this work suggest that the TO treated Ti on TO treated Ti contact pair would have potential tribological applications in engineering. dc.description: open access article
  • Surface Engineering & Coating Technologies for Corrosion and Tribocorrosion Resistance
    dc.title: Surface Engineering & Coating Technologies for Corrosion and Tribocorrosion Resistance dc.contributor.author: Sun, Yong dc.description.abstract: The corrosion of materials leads to about 3 to 4% economic losses of GDP in an industrial nation and also significantly contributes to greenhouse emissions and climate change, as the production of materials is one of the largest greenhouse emitters. Corroded material replacement leads to increasing demands in materials production. Therefore, from economic and environmental points of view, it is highly necessary and important to enhance the corrosion and tribocorrosion resistance of materials. Since corrosion and tribocorrosion are surface- and subsurface-related material degradation phenomena, surface engineering and coating technologies are the most effective to tackle such problems. This reprint is a collection of the papers published in the Special Issue “Surface engineering & coatings technologies for corrosion and tribocorrosion resistance” in the Materials journal. The Special Issue aims to collate the latest developments in this technologically, economically, and environmentally important area. It provides a forum for researchers to share their original work or insight reviews in this field. This reprint contains an Editorial by the Guest Editor and 12 original research papers and reviews related to this topic contributed by researchers from around the globe. The editor acknowledges the contributions of all the authors and the Editorial team in making this Special Issue a success dc.description: This is a reprint of articles from the Special Issue published online in the open access journal Materials (ISSN 1996-1944) (available at: www.mdpi.com/journal/materials/special_issues/Surface_ Tribocorrosion)
  • Surface Engineering & Coating Technologies for Corrosion and Tribocorrosion Resistance
    dc.title: Surface Engineering & Coating Technologies for Corrosion and Tribocorrosion Resistance dc.contributor.author: Sun, Yong dc.description: open access article
  • Tribocorrosion Behavior of γ′-Fe4N Nitride Layer Formed on Mild Steel by Plasma Nitriding in Chloride-Containing Solution
    dc.title: Tribocorrosion Behavior of γ′-Fe4N Nitride Layer Formed on Mild Steel by Plasma Nitriding in Chloride-Containing Solution dc.contributor.author: Sun, Yong; Richard, Bailey dc.description.abstract: Nitriding has long been used to engineer the surfaces of engineering steels to improve their surface and subsurface properties. The role of the surface compound layer (’-Fe4N and/or -Fe2-3N) in improving the tribological and corrosion resistant properties of nitrided steels has been established. However, there have been very few studies on the response of the compound layer to tribocorrosion in corrosive environments. In this work, the tribocorrosion behaviour of a 5 m thick ’-Fe4N nitride layer produced on mild steel (MS) by plasma nitriding has been studied in a NaCl containing so-lution under various electrochemical conditions. The results show that at a cathodic potential of -700 mV (saturated calomel electrode, SCE), where mechanical wear is predominant, the total material removal (TMR) from the ’-Fe4N layer is 37% smaller than that from the untreated MS, and at open circuit potential, TMR from the layer is 34% smaller than that from the untreated MS, while at an anodic potential of -200 (SCE), the ’-Fe4N layer can reduce TMR from mild steel by 87%. The beneficial effect of the ’-Fe4N nitride layer in improving the tribocorrosion behavior of mild steel is derived from its high hardness and good corrosion resistance in the test solution and its ability resist both mechanical wear and corrosion and to reduce wear-corrosion synergism. dc.description: open access article
  • Comparison of wear performance of low temperature nitrided and carburized 316L stainless steel under dry sliding and corrosive-wear conditions
    dc.title: Comparison of wear performance of low temperature nitrided and carburized 316L stainless steel under dry sliding and corrosive-wear conditions dc.contributor.author: Sun, Yong; Bailey, Richard dc.description.abstract: 316L austenitic stainless steel was plasma nitrided and carburized at low temperatures to produce precipitation-free nitrided and carburized layers, respectively. The reciprocation sliding wear performances of the untreated, nitrided and carburized specimens were compared under both unlubricated (dry) and corrosive (in 0.5M H2SO4 solution) conditions. The results show that under dry sliding conditions, both the nitrided layer and carburized layer can offer good wear resistance to 316L steel. The total material loss (TML) of the steel is reduced by more than two orders of magnitude by low temperature nitriding, while low temperature carburizing offers a reduction in TML by an order of magnitude. The better dry sliding wear performance of the nitrided layer is attributed to its much higher hardness as compared to the carburized layer. However, under corrosive-wear conditions in 0.5 M H2SO4 solution, the wear performance of the nitrided layer is significantly deteriorated, with TML 100% higher than that of the untreated 316L steel. On the other hand, the carburized layer can still offer good wear resistance in the corrosive environment, with a reduction in TML of 316L steel by 40%. This research has practical implication that low temperature nitriding is the most suitable for applications in dry and non-corrosive environments, while low temperature carburizing is more suitable for applications in H2SO4-containing corrosive environments. dc.description: The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.
  • Tribocorrosion performance of 316L stainless steel enhanced by laser clad 2-layer coating using Fe-based amorphous powder
    dc.title: Tribocorrosion performance of 316L stainless steel enhanced by laser clad 2-layer coating using Fe-based amorphous powder dc.contributor.author: Ji, Xiulin; Luo, Chanyuan; Jin, Juan; Zhang, Yingtao; Sun, Yong; Fu, Li dc.description.abstract: To improve the tribocorrosion performance of 316L stainless steel (SS), multi-layer (1, 2 and 3 layers) Fe-based alloy coatings were manufactured by laser cladding Fe-based amorphous powder on 316L SS, and the corrosive wear behavior was investigated against Alumina ball in Ringer's solution. With the increase of cladding layer number, the content of bodycentered cubic (BCC) phase increases, and the hardness also improved. The volume loss rate of SS at 5 N load decreased over 3 times by the 2-layer coating. Under 10 or 20 N loads, the 2-layer coating still presents the best tribocorrosion performance with the lowest values of friction coefficient and volume loss rate. The multi-layer cladding caused surface chemical composition change leading to the decrease of Cr accompanied with the increase of Mo and Y, which is responsible for the increase of BCC content and hardness as well as the formation of lubricant FeeCr hydroxide film. The friction induced lubricating film may facilitate to design new metallic coatings for the low carbon steels applied in corrosive environment. dc.description: open access article

Click here to view a full listing of Yong Sun's publications and outputs.

Research interests/expertise

Surface Engineering & Coating Technologies for Tribological, Corrosion Resistance and Biomedical Applications

Characterisation of Surface Engineered Systems.

Plasma Nitriding of Ferrous and Non-ferrous Alloys

Duplex Treatments

Magnetron Sputter Deposition of Oxide, Boride and Nitride Coatings

Surface Engineering of Stainless Steels

Surface Nanocrystalline Materials

Finite Element Analysis

Tribology and Corrosion of Coatings

Tribocorrosion

Surface Engineering of Wear Components for Food Processing

Areas of teaching

Materials Science

Composite Materials

Engineering Science

Failure Analysis

Materials and Sustainability

Green Design

Design for manufacturing

Solid Mechanics 

Qualifications

BSc, Ph.D

Courses taught

Mechanical Engineering BEng

Mechanical Engineering MSc

 

Membership of professional associations and societies

Member of ASM International and Affiliated Heat Treatment Society

Senior Fellow, HEA

Conference attendance

Thin Films'2018, July 2018, Shenzhen, China, invited speaker and session chair

The 8th International Conference on Plasma Surface Engineering AEPSE 2011: Invited Speaker and Session Chair, , Dalian, China, September 2011

Consultancy work

Area of expertise:

Surface treatments

Failure analysis

Materials selection

Previous consultations:

Generation 2 potato slicing blades: wear and failure analysis, Industrial consultant project for PepsiCo Inc., 2007

Surface treatments for potato slicing blades for improved lifespan, Industrial consultant project for PepsiCo Inc., 2008

Current research students

 Mr. Hafiz M.A. Ali: PhD student, Second supervisor

Externally funded research grants information

The Royal Society-NSFC Costshare International Exchange, 2017-2019.

Internally funded research project information

DMU RIF funding, 2014, Development of a novel 2-dimensional sliding wear test facility.

DMU Research Capital Infrastructure Funding (RCIF): to develop the Materials Laboratory for teaching and surface engineering research, 2009

DMU Fee-only PhD scholarship Award: 2011

Published patents

Bell, Thomas and Sun, Yong: Process for the treatment of austenitic stainless steel articles

UK Patent ZSR455/Q036333PGB, 1997

United States Patent 6238490, May 29, 2001.

Professional esteem indicators

220+ publications

Citation: more than 7500 times

h-index: 48 (Google Scholar)

Editorial board member: Surface Technology

Editorial board member: Journal of Biomaterials

Editor: special issue "Tribocorrosion of Surface Engineered Materials", Lubricants (Journal), 2018-2019.

Editor: special issue "Surface Engineering & Coating Technologies for Corrosion and Tribocorrosion Resistance", Materials (Journal), 2020-2022.

Service as reviewer for the following international journals:

  • Surface and Coatings Technology 
  • Surface Engineering 
  • Corrosion Science 
  • Journal of Materials Science 
  • Materials & Design 
  • Vacuum 
  • Materials Chemistry and Physics 
  • Journal of Physics and Chemistry of Solids 
  • Proceedings of the Institute of Mechanical Engineers 
  • Tribology International 
  • Tribology Letters 
  • Applied Surface Science 
  • Iranian Journal of Engineering 
  • Thin Solid Films
  • Wear
  • Materials
  • Lubricants

ORCID number

0000-0002-2489-8914