Pradeep L Menezes

• Ph.D
• Professor (Assistant) at University of Nevada, Reno

This study investigates the tribological properties of cold-sprayed (CS) coatings comprising Cu, Cu-Al2O3, and Cu-Al2O3-Ag at room temperature and under high-temperature sliding conditions. The composite coatings feedstock maintained a constant 50 vol.% Al2O3 concentration, while Cu-Al2O3-Ag had Ag infused at 5 and 10 vol.%, maintaining an overall...

This study investigated the potential of inedible mustard oil (MO) (Brassica juncea) as a suitable bio-lubricant for enhanced thermal, oxidative stability, and tribological performance. To improve the MO's oxidative stability, it was subjected to a chemical epoxidation reaction, forming epoxidized mustard oil (EMO). The MO and EMO were evaluated fo...

Stress corrosion cracking (SCC) failures of austenitic stainless steel (ASS)-based dry storage canister (DSC) weld joints are a potential safety hazard in nuclear applications. The present study aims to provide deeper insights into the effect of novel laser shock surface patterning (LSSP) on the SCC resistance of DSC weld joints. The LSSP experimen...

The stainless-steel weld joints of dry storage canisters (DSC) used for storing spent nuclear fuel are highly susceptible to stress corrosion cracking (SCC). This is a serious safety concern in the nuclear industry as it releases nuclear radiation from interim storage locations. To mitigate this issue, the present study utilizes laser shock peening...

In an effort to improve the fretting corrosion resistance of cold spray (CS) additively manufactured 316L stainless steel (SS), friction stir processing (FSP) was applied as a post-processing surface modification technique. The change in wear-corrosion synergy and degradation was evaluated by assessing changes in mechanical, chemical, and elemental...

In the present work, commercially pure aluminum (Al) powders were milled at cryogenic temperatures (a) without magnesium (Mg) and (b) with 5 wt.% Mg powders for different durations. The cryomilled powders were analyzed using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and x-ray diffraction (XRD) to determine the chan...

Cold spray additive manufacturing (CSAM) has gained significant attention for its rapid solid deposition capabilities. However, the presence of defects such as pores and voids limits its performance, particularly in electrochemical environments. In this study, a novel post-surface treatment, plasma electrolytic oxidation (PEO), was applied and inve...

Within the automotive field, there has been an increasing amount of global attention toward the usability of combustion-independent electric vehicles (EVs). Once considered an overly ambitious and costly venture, the popularity and practicality of EVs have been gradually increasing due to the usage of Li-ion batteries (LIBs). Although the topic of...

The present study investigates the application of friction stir processing (FSP) on the degradation (wear, corrosion, and wear-corrosion synergism) response of cold spray additive manufactured (CSAM) 316L SS components. All tribological-based tests were conducted using a reciprocating ball-on-flat configuration in 3.5 wt% NaCl solution. Each degrad...

Machine learning (ML) algorithms have brought about a revolution in many industries where otherwise operation time, cost, and safety would have been compromised. Likewise, in lubrication research, ML has been utilized on many occasions. This review provides an in-depth understanding of seven ML algorithms from a tribological perspective. More speci...

In nuclear applications, the utilization of austenitic-based stainless steel (ASS) components is an ideal material choice for storing spent nuclear fuels in dry storage canisters (DSC). However, due to the chloride rich environ- ments in which they operate, failure in the form of stress corrosion cracking (SCC) frequently occurs. The follow- ing st...

In this study, plastic oil (PO) as a potential lubricant was investigated. The base PO was incorporated with graphene nanoplatelets (GNP) and hexagonal boron nitride (hBN) nano additives in varying concentrations to form nano lubricants. Their viscosity, tribological, acidic/basic nature, thermal degradation and dispersion stability properties were...

Ni-based superalloys have been extensively employed in the aerospace field because of their excellent thermal and mechanical stabilities at high temperatures. With these advantages, many sought to study the influence of fusion-reliant additive manufacturing (AM) techniques for part fabrication/reparation. However, their fabrication presents many pr...

In the present investigation, nanocrystalline (NC) materials, such are pure Al and Mg-doped Al were manufactured using cryo-milling followed by the spark plasma sintering process. The changes in crystallite size were determined using X-ray diffraction. Hardness measurements were performed using vickers micro-hardness tester. The friction and wear p...

In this investigation, pure aluminum (Al) powders were cryomilled with and without magnesium dopants to study (a) the effect of cryomilling time on the crystallite size and (b) the effect of magnesium dopant on Al to achieve grain boundary stability. The cryomilling process was carried out using liquid nitrogen for different durations. The characte...

In recent years, cold spray additive manufacturing (CSAM) has become an attractive technology for surface modification and protection. However, due to the intrinsic porous nature of CSAM coatings, they suffer from rapid material degradation due to premature brittle fracturing induced by tribological interactions. In this work, laser shock peening (...

The degradation due to high friction, wear, and corrosion of mechanical components for industrial applications has invoked substantial economic loss. In recent years, scientists and engineers have developed techniques to mitigate the issues associated with this deterioration potentially. Among these developed techniques, controlling the coefficient...

Acetabular cups, which are among the most important implants in total hip arthroplasty, are usually made from titanium alloys with high porosity and adequate mechanical properties. The current three-dimensional (3D) printing approaches to fabricate customized acetabular cups have some inherent disadvantages such as high cost and energy consumption,...

Small living organisms such as lizards possess naturally built functional surface textures that enable them to walk or climb on versatile surface topographies. Bio-mimicking the surface characteristics of these geckos has enormous potential to improve the accessibility of modern robotics. Therefore, gecko-inspired adhesives have significant industr...

Friction stir processing (FSP) was employed as a post-surface processing technique to modify the tribological and corrosion behavior of cold-sprayed (CS) 316 L SS deposits. Results indicate that the effect of FSP induced an austenitic phase transformation due to the combination of frictional heat and plastic deformation. Consequentially, the fricti...

The friction and wear behavior of bio-based trihexyltetradecylphosphonium saccharinate [P6,6,6,14][Sacc] and halogen-based trihexyltetradecylphosphonium bis(trifluoromethylsulfonyl) amide [P6,6,6,14][NTF2] ionic liquids (ILs) were studied to understand their lubrication mechanisms at steel sliding interfaces. The physicochemical and tribological pr...

In additive manufacturing (AM), selective laser melting (SLM) is a relatively novel technique that utilizes thermal energy via laser beams to melt and solidify metallic powders into three-dimensional components. Compared to traditional manufacturing techniques, SLM is advantageous because it is more time-efficient, cost-effective, and allows for th...

In the current study, pure aluminum (Al) powders were cryomilled with and without 3 wt.% pure magnesium (Mg) dopant for varying durations followed by spark plasma sintering (SPS) of powders to prepare bulk components with superior mechanical properties. The crystallite sizes were determined for powders and the bulk components by analyzing the X-ray...

Laser cladding (LC) is a laser-based surface modification technique widely adopted to develop a thin coating or remanufacture worn-out mechanical components that work in extreme conditions. LC helps to generate superior surface properties and surface integrity on the substrate surface, improving the service life. This review paper provides a compre...

The present work reports the utilization of laser treatment for the structuring of a B2O3 coating on ceramic substrates. The two ceramic substrates, pure Al2O3, and Al2O3-20wt% B2O3, were prepared in-house using cold pressing and sintering route. The coatings were prepared by applying the ethanol-B2O3 slurry on the ceramic substrate using a dip coa...

Potential engineering applications of Magnesium (Mg) and Mg-based alloys, as the lightest structural metal, have made them a popular subject of study. However, the inferior corrosion and wear characteristics significantly limit their application range. It is widely recognized that surface treatment is the most commonly utilized technique for remark...

Graphene is an attractive material for many applications due to excellent inherent properties such as lower density, high mechanical strength, higher thermal conductivity, etc. However, it has been used as an additive material due to size limitation. To overcome the size limitation without affecting the inherent properties of 2D graphene sheets, re...

In recent years, the demand for advanced high-strength steel (AHSS) has increased to improve the durability and service life of steel structures. The development of these steels involves innovative processing technologies and steel alloy design concepts. Joining these steels is predominantly conducted by following fusion welding techniques, such as...

Cermet is an advanced class of material consisting of a hard ceramic phase along with a metallic binding phase with the combined advantages of both the ceramic and the metal phase. The superior properties of this class of materials are particularly useful in high-temperature, tribological, and machining applications. This review paper seeks to prov...

The wettability of ionic liquids (ILs) is relevant to their use in various applications. However, a mechanistic understanding of how the cation-anion pair affects wettability is still evolving. Here, focusing on phosphonium ILs, wettability was characterized in terms of contact angle using experiments and classical molecular dynamics simulations. B...

This work focuses on understanding the influence of grain boundary (GB) character on magnesium (Mg) dopants segregation in nanocrystalline (NC) aluminum (Al) using a hybrid Monte Carlo/molecular dynamics (MC/MD) framework. Studies are done to identify the dopant segregation behavior in symmetric (Σ3) and asymmetric Σ5, Σ7, Σ9, Σ11, Σ13 and Σ61 tilt...

The aim of this study was to develop a novel set of Al2O3-B2O3-CuO composites and evaluate their tribological performance at varying humidity (10-95% relative humidity) levels. First, the Al2O3-B2O3 composites were prepared using cold press sintering by varying the amount of B2O3 (5-20 wt.%). The results revealed that an increase in B2O3 content in...

Ultrasonic nanocrystal surface modification (UNSM) is a unique, mechanical, impact-based surface severe plastic deformation (S2PD) method. This newly developed technique finds diverse applications in the aerospace, automotive, nuclear, biomedical, and chemical industries. The severe plastic deformation (SPD) during UNSM can generate gradient nanost...

A novel set of Al2O3-B2O3-CaO composites were manufactured using a cold press-sintering. The B2O3 content in the composites was varied from 5-20 wt.% and 2 wt.% CaO was added to the composites. Dry sliding tests were conducted against an alumina ball at 10-95% relative humidity. The presence of the in-situ formed aluminum borate in the composite en...

Phosphonium ionic liquids (ILs) have various uses, including as environmentally benign lubricants and lubricant additives. The properties and behavior of these ILs depend on their chemical composition, i.e., cation and anion combination, and the operating conditions. One approach to understanding the relationships between composition, conditions, a...

High entropy alloys (HEAs) are the outstanding innovations in materials science and engineering in the early 21st century. HEAs consist of multiple elements with equiatomic or near equiatomic compositions, which exhibit superior mechanical properties, such as wear resistance, fatigue resistance, and corrosion resistance. HEAs are primarily used in...

The application of tribology is not just limited to mechanical components of engineering systems. As a matter of fact, the understanding of friction and wear can be applied to everyday life. One of the important fields is skin tribology, as human skin interacts with various surfaces of different materials. This paper focuses on the friction behavio...

The present work focuses on manufacturing bulk nanocrystalline Al-Mg alloys using cryomilling and high-pressure cold spray (HPCS) techniques. The Al and 5 wt. % Mg powders were pre-mixed and cryomilled for 2, 4, 6, and 8 hours. The HPCS technique was utilized to deposit cryomilled powder onto the Al substrate. After deposition, the thick deposited...

For the first time, Zr702 coatings were deposited onto an Al6061 alloy using a high-pressure cold spray (HPCS) system. In this work, five different N2 process gas temperatures between 700 and 1100 °C were employed to understand the formation of cold sprayed (CS) Zr coatings and their feasibility for enhanced wear resistance. Results indicated that...

The present investigation aims to develop nanocrystalline (NC) pure aluminum powders using cryomilling technique and manufacture bulk components using spark plasma sintering (SPS). The cryomilling was performed on pure Al powders for 2, 6, and 8 h. The cryomilled powders were then consolidated using SPS to produce bulk components. The particle morp...

The thermal stability of ionic liquids is important for their use in a variety of applications. Here, reactive molecular dynamics simulations and thermogravimetric analysis were used to explore the thermal decomposition mechanisms of phosphonium salicylate and phosphonium benzoate. Experiments performed at different heating rates indicated that the...

In this work, the wear and corrosion behavior of high-pressure cold-sprayed (CS) 316 L stainless-steel (SS) was investigated and compared with traditional 316 L SS for pharmaceutical component repairing/refurbishing. It was observed that the CS deposit exhibited a compact microstructure with a greater percentage of the ferrite phase. The effect of...

Due to their superior mechanical properties, formability, corrosion resistance, and lightweight nature, 6xxx series aluminum (Al) alloys are considered as a promising structural material. Nevertheless, the successful application of these materials depends on their response to the external environment. Recently, designers considered the surface prop...

The tribological parameters in sliding/rolling mechanism have significant role in overall performance of the materials. To design a material that offers low friction and wear, the material must have specific mechanical and physical properties. In this context the lubrication has important role and it is known that lubrication can reduce the undesir...

The extreme environmental applications of solid lubricants attained a greater interest to the researchers and product designers. This chapter deals with the processes, mechanisms, properties, and materials for solid lubricants and its real-time applications are established. Reliable and wear-resistive solid lubricants developments are carried out w...

Alumina is a widely used ceramic for tribological applications such as gears, bushings, bearings, etc. due to its chemical and physical stability. However, the friction between alumina-alumina is high, which reduces its usage for tribological applications. To overcome the high friction, various solid lubricants can be added in the alumina matrix th...

In the 21stcentury, researchers have turned their attention towards composite materials (CMs) concerning lightweight applications in the automobile sector. Researchers have found a way to achieve better fuel efficiency by substituting conventional materials with novel variants. The history and state-of-the-art applications of composite materials in...

In most tribological applications, liquid or grease based lubricants are used to facilitate the relative motion of solid bodies to minimize friction and wear between interacting surfaces. The challenges for liquid lubricants arise in extreme environmental conditions, such as very high or low temperatures, vacuum, radiation, and extreme contact pres...

As the manufacturing industry continues to advance, functionally graded metallic materials (FGMMs) are becoming more important due to their unique properties and versatile applications. Conventional methods, such as casting, thermal spraying, and chemical vapor deposition, have been widely utilized to produce such FGMMs for long. In recent years, a...

Powder bed fusion is an additive manufacturing technology used to create functional industrial parts and complex 3D geometries, layer by layer, which are not feasible using traditional manufacturing techniques. This processing technique involves spreading a thin layer of powder over the build platform and selectively heating the powder using a heat...

Additive manufacturing (AM) of metals currently sees significant use in the bio-medical and aerospace industries. The ability to rapidly produce highly geometrically complex parts has the potential to save millions of dollars a year and increase efficiency. Furthermore, the AM process enables distributed manufacturing and the ability to produce par...

In recent years, with the development of eco-friendly lubricants, different vegetable oils have been studied and found to improve the overall tribological performance compared to petroleum-based oils. Being one of the commonly used vegetable oils, canola oil has become popular due to its non-toxicity and low cost. However, this bio-lubricant lacks...

This paper discusses the effect of LSP on residual stress in ASS 304L welds and its influence on the SCC of DSC’s used to store spent nuclear fuels.

Ultrasonic surface rolling process (USRP) is a novel surface severe plastic deformation (SPD) method that integrates ultrasonic impact peening (UIP) and deep rolling (DR) to enhance the surface integrity and surface mechanical properties of engineering materials. USRP can induce gradient nanostructured surface (GNS) layers on the substrate, providi...

Phosphonium-based room temperature ionic liquids (P-RTILs) offer outstanding lubricant properties. Studies have shown that the cationic chain length and anionic ring size significantly affect the performance of P-RTIL lubricants by altering properties, such as viscosity, density, thermal stability, wettability, and solubility. Functionalized moieti...

Nanostructuring is a commonly employed method of obtaining superior mechanical properties in metals and alloys. Compared to conventional polycrystalline counterparts, nanostructuring can provide remarkable improvements in yield strength, toughness, fatigue life, corrosion resistance, and hardness, which is attributed to the nano grain size. In this...

High-entropy alloys (HEAs) are composed of multiple elements with equimolar or near equimolar composition that have superior mechanical and tribological properties. In this article, we present a review on the tribological performance of HEAs. The tribological properties of different HEAs systems have been evaluated, and it has been found that the w...

Ionic liquids (ILs) represent a new class of green lubricants that exhibit superior lubrication performance compared to conventional lubricants. Further, solid particle additives, particularly lamellar solid particles to enhance the tribological properties of base oils, are well known. In the current investigation, various sizes, shapes, and types...

Lubrication for extreme conditions, such as high temperature, cryogenic temperature, vacuum pressure, high load, high speed, and corrosive environments, is a continuing challenge among tribologists and space engineers due to the inadequate friction and wear properties of liquid lubricants. As a result, tremendous research effort has been put forwar...

Electroactive polymers (EAPs) are an advanced family of polymers that change their shape through electric stimulation and have been a point of interest since their inception. This unique functionality has helped EAPs to contribute to versatile fields, such as electrical, biomedical, and robotics, to name a few. Ionic EAPs have a significant advanta...

The eventual material degradation of steel components in bio-implant, marine, and high-temperature applications is a critical issue that can have widespread negative ramifications from a safety and economic point of view. Stemming from their tribological, corrosion, and erosion-based properties, there is an increasing need to address these issues e...

In the current investigation, an equiatomic mixture of Ni and Ti was coated on the mild steel substrate by atmospheric plasma spray coating technology. The coating process was performed by varying the primary gas flow rate and plasma arc current process parameters. The microhardness and adhesion strength of the coating was evaluated after successfu...

Nanocrystalline metals are generally unstable due to a large volume fraction of high-energy grain boundaries associated with a small grain size. Preferential dopant segregation to the high-energy grain boundaries is observed to enhance the stability of the material’s microstructure by minimizing its energy. Nanocrystalline aluminum-dopant systems w...

Water-based lubricants (WBLs) have been at the forefront of recent research, due to the abundant availability of water at a low cost. However, in metallic tribo-systems, WBLs often exhibit poor performance compared to petroleum-based lubricants. Research and development indicate that nano-additives improve the lubrication performance of water. Some...

Surface modification methods have been applied to metals and alloys to change the surface integrity, obtain superior mechanical properties, and improve service life irrespective of the field of application. In this review paper, current state-of-the-art of peening techniques are demonstrated. More specifically, classical and advanced shot peening (...

Currently soft robots primarily rely on pneumatics and geometrical asymmetry to achieve locomotion, which limits their working range, versatility, and other untethered functionalities. In this paper, we introduce a novel approach to achieve locomotion for soft robots through dynamically tunable friction to address these challenges, which is achieve...

Plasma electrolytic oxidation (PEO) is a novel surface treatment process to produce thick, dense metal oxide coatings, especially on light metals, primarily to improve their wear and corrosion resistance. The coating manufactured from the PEO process is relatively superior to normal anodic oxidation. It is widely employed in the fields of mechanica...

We are pleased to publish a Special Issue on “Additively Manufactured Coatings” that is intended to provide peer-reviewed articles in the fascinating field of coatings, particularly in the area of additive manufacturing technology [...]

DLC coatings have attracted an enormous amount of interest for science and engineering applications. DLC occurs in several different kinds of amorphous carbon materials. Owing to the extensive diversity in their properties, DLC coatings find applications in mechanical, civil, aerospace, automobile, biomedical, marine, and several other manufacturin...

In the present work, the effect of graphite nanoplatelets (GNPs) on tribological properties of the aluminum (Al), and Al/alumina (Al2O3) composite are studied. GNPs are multilayer graphene sheets which were used as a solid lubricant material. Two sets of composites, Al/GNPs and Al/GNPs/Al2O3 with varying amounts of reinforcements, were synthesized...

Graphite nanoplatelets (GNPs) as an oil nano additive has gained importance to enhance the lubrication properties of renewable lubricants, such as vegetable oils. Using appropriately processed GNPs is necessary to gain the required tribological advantage. The present study investigated ball-milled GNPs, to understand the effect of GNPs concentratio...

3D printing in the textile and fashion industry is a new emerging technology. Applications of 3D printing for designing clothes and other wearable accessories require tribological and biological understanding of 3D printing plastics against the complex human skin to mitigate skin-friction related ailments such as calluses and blisters. This study p...

Additive manufacturing (AM) by laser powder bed fusion (LPBF) has gained significant research attention to fabricate complex 3D Inconel alloy components for jet engines. The strategic advantages of LPBF-based AM to fabricate jet components for aerospace applications are well reported. The jet components are exposed to a high degree of vibration dur...

First Prize in the recognition of the outstanding publication "Fiber-Reinforced Polymer Composites: Manufacturing, Properties, and Applications. Polymers 2019, 11, 1667. https://doi.org/10.3390/polym11101667"