Mass Loss Behavior Research Articles

Combustion and mass loss behavior and characteristics of a single biomass pellet positioning at different orientations in a fixed bed reactor

This study aims to investigate the combustion characteristics and mass loss behaviors of rice straw and wheat straw biomass pellets experimentally in a laboratory fixed bed combustor under various operating conditions. High-speed photography was used to record images of the combustion process, and a sensitive balance was utilized for recording the particle mass history during the combustion process in addition to K-type thermocouples for temperature measurements. For both materials, the single pellet was exposed to various air temperatures and different flow rates of air. The orientation of the biomass pellet was positioned at various angles from 0 (horizontal), 30°, 45°, 60° (inclined), and 90° (parallel) to the hot air stream at different flow rates. Both glowing reactions and flameless ignition have been noticed in all experiments at all pellet orientations. All pellets experienced low and high luminosity volatiles without flames, followed by a bright radish color and short-lived combustion of the chars. Although the volatile contents of the two materials are identical, the volatile combustion duration of wheat straw (17–258 s) is less than that of rice straw (20–300 s), which could be due to differences in particle sizes, shapes, and structural compositions. The results also show that increased air temperatures lessen the time it takes for volatile and char to ignite and burn off. It also raises the temperature of surface ignition. Starting from the horizontal position and increasing the orientation angle of the pellet, the volatile and char ignition times increase up to 30° and then drop up to 90°, with angle 45° giving the lowest value. The same pattern was also noticed for volatile and char burnout times. The pellet horizontal position (0°) exhibits reduced combustion and mass loss (%) time intervals. The order of increasing the maximum temperature at the pellet surface was 30° > 60° > 90° angles. Increasing the air temperature reduces the times of char combustion, devolatilization, volatile burnout, and char burnout. As the air flow rate increases, the effect on the combustion parameters alternates between increasing and decreasing values.

Effect of early‐strengthening of RC beams using UHPC layers on their performance against reinforcement corrosion

AbstractIn the present work, the effect of early‐strengthening of reinforced concrete (RC) beam specimens using layers of ultra‐high performance concrete (UHPC) on their performance against reinforcement corrosion was examined. A number of fifteen RC beam specimens were prepared, one beam specimen uncorroded and unstrengthened was considered as a control beam, two beams were corroded and unstrengthened, and twelve corroded and strengthened beam specimens that were divided into two groups. RC beam specimens of the first group were corroded continuously to cause total theoretically targeted mass losses of the steel rebars and then strengthened using UHPC layers. RC beams of the second group were also corroded to the same degrees but in two steps. In the first step, the beams were corroded to cause a portion of targeted theoretical mass losses. Then the beams were strengthened in the same way as the beams of the first group and then subjected to second‐step accelerated reinforcement corrosion to achieve finally the same degrees of total theoretical mass losses as that of the first group. The corroded and strengthened beam specimens were exposed to flexural testing, and then the corroded rebars extracted from the beams were used to conduct gravimetric tests to determine the actual values of the mass losses due to accelerated corrosion. The gravimetric and flexural tests' results were used mainly to observe the influence of early‐strengthening on the actual mass loss and the flexural behavior of the tested beam specimens. Results showed a significant reduction in the values of the actual mass loss and better flexural behavior due to the early‐strengthening of the corroded beams. An analytical model, developed and validated using the data collected from the experimental tests, can be utilized to predict the ultimate load‐carrying capacities of the corroded strengthened RC beam specimens.

Physico-geometrical Kinetic Aspects of the Thermal Dehydration of Trehalose Dihydrate

When linearly heating trehalose dihydrate (TH-DH) at a relatively high heating rate (β ≥ 1.5 K min–1), the thermal dehydration begins in the solid state and transitions to the liquid state at the melting point of TH-DH (∼370 K). The complex mass loss and phase change characteristics observed during the thermal dehydration is due to the contributory effects of various physical phenomena, including melting of TH-DH and anhydride products. The reactions entirely occurred in the solid state under isothermal and nonisothermal conditions at a low heating rate (β ≤ 1.0 K min–1), and its kinetics were described by the physico-geometrical consecutive process comprising the surface reaction and subsequent phase boundary-controlled reaction. The reactions initiated at approximately the melting point of TH-DH under a significantly high atmospheric water vapor pressure and proceeded mostly in the liquid state exhibiting a single-step mass loss behavior. The thermal dehydration accompanied by liquefaction demonstrated an autocatalytic kinetic behavior, which was regulated by the evaporation of the water vapor from the surface of viscous liquid particles. The kinetic findings for the reactions in the solid and liquid states allow the physico-geometrical interpretation for the complex mass loss and phase change behaviors during heating TH-DH at relatively high β values.

Steam gasification of yak manure: Kinetic modeling by a sequential and coupling method

Considering yak manure’s low moisture and biomass-rich properties, steam gasification to produce hydrogen-rich gas provides a feasible approach for waste management and energy usage, which is important in Tibet regions. Prior to large-scale application, kinetic study of the multi-stage thermochemical process is necessary for mechanistic understanding and process design. By employing a sequential and coupling method, a comprehensive kinetic model was built to elucidate reaction mechanisms of each stage, and key kinetic parameters were obtained with the help of Flynn-Wall-Ozawa (FWO)/Kissinger-Akahira-Sunose (KAS), Coats-Redfern (CR)/Kissinger and distributed activation energy model (DAEM) methods. The effects of steam concentration and heating rate on mass loss behavior and gaseous product evolution were examined. During the thermal decomposition, the presence of steam slightly inhibited the pyrolysis reaction, and significantly improved the gas–solid reactions when steam concentration was over 20 %. For pyrolysis stage, the activation energy associated was around 175 kJ/mol. For gas–solid reaction stage, parallel reactions including both char condensation (215 kJ/mol) and steam-char reaction (307 kJ/mol) were confirmed by DAEM modelling. Based on Thermal Gravimetric Analysis (TGA) study, investigation of yak manure steam gasification to produce hydrogen-rich gases was further conducted in a semi-batch reactor by changing temperature and steam flow rate. It was found that the increase of temperature greatly promoted tar cracking and gas–solid reactions. Temperature and steam flow rate exerted positive impacts to increased hydrogen concentration of dry gas through enhanced water–gas shift reactions.

Microscopic mechanism of contraction of tension wood G-fiber due to boiling

Many woody eudicot plants form a secondary xylem composed of gelatinous fibers (G-fibers) called "tension wood" (TW) along the upper side of the tilted stem or branch. TW generates a large tensile growth stress in the longitudinal direction, allowing the tilted stem or a branch to develop negative-gravitropism in response to the strong gravitational stimulus. This is because the G-fiber tends to contract in the longitudinal direction as it matures. The matured G-fiber also contracts upon boiling in water (= hygrothermal treatment, i.e., HT-treatment), and moisture desorption (= drying treatment). These contractions occur in the cellulose-rich gelatinous layer (G-layer) as an innermost layer of the G-fiber. It is still an unsolved mystery how the G-layer, which is composed of highly crystallized and longitudinally oriented cellulose microfibrils (CMFs), contracts during maturation, boiling, and drying. In the present study, TW specimen of Konara oak (Quercus serrata L.) was subjected to HT-treatment under different temperature and time conditions, and strain due to treatment was followed. Besides, the mass loss due to HT-treatment was also followed. Obtained results are summarized as follows. (1) Green TW specimen of Konara oak contracted in the longitudinal direction when subjected to the HT-treatment at a treatment temperature higher than 40 °C, which eventually converged to a constant value according to each treatment temperature. Magnitude of the longitudinal HTR-strain in the TW specimen was positively correlated with the treatment temperature in the range from 40 to 120 °C, whereas in the normal wood (NW) specimen, it does not occur explicitly when the temperature is less than 100 °C. (2) Both TW and NW specimens showed mass loss when subjected to the HT-treatment. The mass loss rate increased rapidly by the HT-treatment at 120 °C, while it was only slight below 100 °C. There was no significant difference between the mass loss behavior of TW and NW by the HT-treatment. From analyzing those results, physical behavior of CMF and other non-cellulosic matrix components in the G-layer during the HT-treatment was estimated. The discussion was further developed to associate HT-contraction with microscopic mechanisms of the other two characteristic contractions of the G-fiber, i.e., maturation strain and drying shrinkage.

Implications of data smoothing on experimental mass loss rates

Time resolved mass loss rate (MLR) is a commonly reported metric in fire safety science and is a measurement often characteristic of a high degree of noise. Such noise encourages the use of various smoothing techniques to illustrate average MLR behavior. A study was conducted to observe the influence of data smoothing techniques on experimentally determined mass loss rates. Methodologies including numerical differentiation techniques, the standardized ASTM E1354/ISO 5660 method, simple moving averages, and the Savitzky-Golay filter were applied to MLR data from charring (timber) and non-charring (PMMA and PA6) solids. Transient behavior such as charring and determining the MLR at ignition are particularly influenced by the choice of processing scheme. The peak MLR for charring materials was truncated up to 30% when using high-order filters (50-Pt Moving Average or 51-Frame Length Savitzky-Golay). This work outlines a novel integral method through which the user can quantify the degree to which a given smoothed MLR curve fits the true observed mass loss behavior. No single approach to processing MLR data can fully capture the variation associated with the material and instrumentation used; therefore careful consideration should be taken when smoothing MLR data.

The Effect of Shot Blasting Process on Mechanical Properties and Anti-Corrosive Behavior of Steel Reinforcement

The need to confront the problem of corrosion resistance of steel reinforcement is an issue of major importance and a perpetual challenge to the structural integrity and reliability in reinforced concrete (RC) structures. The current experimental study presents the results of the combined effect of shot blasting and coating on steel reinforcing bars in respect to their anticorrosive resistance and their mechanical behavior, at various times of exposure to corrosive environment. In the present manuscript, a comparison of different abrasive materials was primarily conducted, via electrochemical measurements (Tafel tests), to estimate the corrosion current (icorr) for each abrasive material. After the indication that corrosion resistance can be modified by shot blasting with corundum, the method of Zn85Al15 coating was chosen to further investigate the combined effect of shot blasting with coating, in terms of percentage mass loss and mechanical behavior of steel reinforcement. The results demonstrated that, upon the completion of the surface treatment process with corundum, the mechanical performance of steel bars was improved in terms of ductility. Moreover, the Zn85Al15 coating provided a satisfactory anticorrosive protection to steel bars in the entire exposure period of accelerated corrosion. The combined contribution of shot blasting and coating processes was deemed to be very encouraging and may trigger further investigation and research, for the production of a better corrosion resistance of B500c steel.

Weakening the wind with ULLYSES: Examining the Bi-Stability Jump

AbstractRadiation-driven mass-loss is an important, but still highly debated, driver for the evolution of massive stars. Current massive star evolution models rely on the theoretical prediction that low luminosity massive stars experience a sudden increase in mass loss below a stellar effective temperature of about 20 000 K. However, novel radiation-driven mass-loss rate predictions show no such bi-stability jump, which effects the post main-sequence evolution of massive stars. The ULLYSES data set provides a unique opportunity to investigate the theoretical bi-stability jump dichotomy and may help to assess the existence of the bi-stability jump in massive star winds. By utilising UV spectra from ULLYSES combined with X-shooter optical data we obtain empirical mass-loss rate constraints, that are no longer degenerate to the effects of wind clumping, and derive novel empirical constraints on the mass-loss behavior across the temperature range of the bi-stability jump. Current preliminary results do not show a clear presence of a bi-stability jump.

Evolution of Wolf–Rayet stars as black hole progenitors

ABSTRACT Evolved Wolf–Rayet stars form a key aspect of massive star evolution, and their strong outflows determine their final fates. In this study, we calculate grids of stellar models for a wide range of initial masses at five metallicities (ranging from solar down to just 2 per cent solar). We compare a recent hydrodynamically consistent wind prescription with two earlier frequently used wind recipes in stellar evolution and population synthesis modelling, and we present the ranges of maximum final masses at core He-exhaustion for each wind prescription and metallicity Z. Our model grids reveal qualitative differences in mass-loss behaviour of the wind prescriptions in terms of ‘convergence’. Using the prescription from Nugis & Lamers the maximum stellar black hole is found to converge to a value of 20–30 M⊙, independent of host metallicity; however, when utilizing the new physically motivated prescription from Sander & Vink there is no convergence to a maximum black hole mass value. The final mass is simply larger for larger initial He-star mass, which implies that the upper black hole limit for He-stars below the pair-instability gap is set by prior evolution with mass loss, or the pair instability itself. Quantitatively, we find the critical Z for pair-instability (ZPI) to be as high as 50 per cent Z⊙, corresponding to the host metallicity of the Large Magellanic Cloud. Moreover, while the Nugis & Lamers prescription would not predict any black holes above the approx 130 M⊙ pair-instability limit, with Sander & Vink winds included, we demonstrate a potential channel for very massive helium stars to form such massive black holes at ∼2 per cent Z⊙ or below.

Effects of elevated temperatures on strength and microstructure of mortar containing nano-calcined montmorillonite clay

This study focuses on the residual mechanical strengths and microstructure of nano-calcined montmorillonite clay (NCMC) cement mortars at high temperatures. NCMC was prepared via thermal activation of nano-clay, and the produced mortars with 0%, 1%, 3%, and 5 wt% NCMC replacements were subjected to temperatures of up to 900 °C. The fire-resistance properties of the produced mortars and their role were analysed through thermogravimetric analysis, X-ray diffraction, and scanning electron microscopy.The results revealed that the use of thermally treated NCMC reduced the density and widths of microcracks, improved the mass-loss behaviour, reduced the amount of calcium hydroxide crystals, and strengthened the matrix, which explains their higher residual mechanical strengths.

Thermokinetics of mass-loss behavior on direct reduction of copper slag by waste plastic char

The effective utilization of waste plastics is the key technology for environmental protection. Waste plastic char was proposed as a reductant for recovering valuable metals from copper slag. Reaction reactivity, mass-loss behavior and thermokinetics of copper slag were studied by FTIR and thermogravimetric analyzer. The main functional groups of waste plastic char are benzene ring, C-O and –OH. Mass-loss behavior evaluation method was proposed based on calculating and detection of sample’s total mass-loss and reductant mass-loss.With temperature increasing, reaction mechanism transformed. Three-dimension diffusion and interface’s chemical reaction rate are restrictive steps for the first and the second reaction regime, respectively. For waste plastic char, activation energy of the first regime and second regime are about 289.5 ~ 276.2 kJ/mol and 584.5 ~ 709.9 kJ/mol, respectively. CaO changed the second regime’s activation energy. When CaO added, activation energy of waste plastic char and coal decreased by 119.8 ~ 121.5 kJ/mol and 100.0 ~ 113.6 kJ/mol respectively. Waste plastic char presents better reduction reactivity in the second reduction regime than coal. This research makes it possible for recycling of municipal organic wastes and iron containing slags.

Erodible coatings based on HPMC and cellulase for oral time-controlled release of drugs.

Oral drug delivery systems for time-controlled release, intended for chronotherapy or colon targeting, are often in the form of coated dosage forms provided with swellable/soluble hydrophilic polymer coatings. These are responsible for programmable lag phases prior to release, due to their progressive hydration in the biological fluids. When based on high-viscosity polymers and/or manufactured by press-coating, the performance of functional hydroxypropyl methylcellulose (HPMC) layers was not fully satisfactory. Particularly, it encompassed an initial phase of slow release because of outward diffusion of the drug through a persistent gel barrier surrounding the core. To promote erosion of such a barrier, the use of a cellulolytic product (Sternzym® C13030) was here explored. For this purpose, the mass loss behavior of tableted matrices based on various HPMC grades, containing increasing percentages of Sternzym® C13030, was preliminarily studied, highlighting a clear and concentration-dependent effect of the enzyme especially with high-viscosity polymers. Subsequently, Sternzym® C13030-containing systems, wherein the cellulolytic product was either incorporated into a high-viscosity HPMC coating or formed a separate underlying layer, were manufactured. Evaluated for release, such systems gave rise to more reproducible profiles, with shortened lag phases and reduced diffusional release, as compared to the reference formulation devoid of enzyme.

Morphology details and size distribution characteristics of single-pot-synthesized silica nanoparticles

A series of silica nanoparticles (SNP-1, SNP-2, SNP-3, SNP-4, SNP-5 and SNP-6) were synthesized in ethanol by the hydrolysis and polycondensation reaction of tetraethoxysilane with the aids of water initiator and ammonia catalyst and then investigated in a comprehensive manner in terms of morphological structure by using synchrotron transmission small-angle X-ray scattering and grazing incidence wide-angle X-ray scattering and combined together with dynamic light scattering, scanning electron microscopy, infrared spectroscopy and thermogravimetry. They were confirmed to be successfully synthesized as oblate amorphous ellipsoids (Re=9.70∼56.30nm, equatorial radius; ε=0.78∼0.80, ellipsoidicity) with sharp surfaces in single unimodal and narrow size distributions. The radial density profile details, including two-phases (i.e., less dense core and denser shell), were determined for the first time, in addition to a set of structural parameter details (radius of gyration, radius, core radius, shell thickness, and radius distribution). Larger particle was synthesized conveniently by higher loading of ammonia solution with respect to the silane monomer. The as-synthesized silica particles were found to undergo two-step mass loss behaviors in heat treatment up to 500°C; the first-step loss took place below 120°C due to removals of physically absorbed water molecules and possible solvent residues and the second-step loss above 180°C occurred by removals of water and ethanol byproducts due to the post condensation reactions of hydroxy and ethoxy residues.

Measurement of roller chain wear lubricated with palm oil-based hexagonal boron nitride nanoparticles

Purpose This study aims to introduce a novel technique which helped in quantifying the wear performance of a roller chain which was lubricated by using the palm oil-based hexagonal boron nitride (hBN) nanoparticles (nano-biolubricant). Design/methodology/approach The efficiency of the nano-biolubricant was evaluated by using a custom-made roller chain tribometer, at different resistance torque values at a constant speed and running time. Prior to the test, 2 different lubrication conditions were applied. The mass loss and elongation behaviour of a roller chain was selected as a degradation metric for monitoring the amount of the chain wear. The predominant wear mechanism of a roller chain was identified by surface morphological analysis. Findings Regardless of the lubrication conditions, the wear performance of the roller chain was significantly increased, at increasing resistance torque values. Higher wear was noted when the roller chain was lubricated using a nano-biolubricant, however, the wear curve showed a promising high chain life. The predominant wear mechanism involved is abrasive wear. Originality/value Although an increase in the elongation during running is based on the wear between the pins and roller, none of the earlier studies quantified the wear performance of a roller chain under differing lubrication conditions. Hence, for bridging the gap, this study described a new method for measuring the wear performance of the roller chain which was lubricated using the palm oil-based hBN nanoparticles or a nano-biolubricant. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-02-2020-0061/

Investigation into the co-pyrolysis behaviors of cow manure and coal blending by TG–MS

In this study, the co-pyrolysis characteristics of cow manure (CM) and Meihuajing bituminous coal (MHJ) blends were investigated in detail. The mass loss behavior and gas evolution characteristics of the blends were analyzed online by thermogravimetry–mass spectrometry (TG–MS), and kinetic analysis was performed. The results demonstrate that the addition of CM to the MHJ increases the reactivity of blends, indicating that interaction between the CM and MHJ occurred during co-pyrolysis. For conventional gases, the release order of gases during CM and MHJ blend pyrolysis is H2O, CO2, CO, CH4, H2. For sulfur-containing gases, with increasing proportion of CM, the emissions of H2S, COS, and C4H4S increase and that of SO2 decrease, and the release temperature interval shifts to lower directions. The Coats & Redfern model was used, an increase of activation energy with CM addition was observed. The optimum blending ratio based on the lowest activation energy is CM:MHJ = 1:3 and the activation energy is 41.9 kJ/mol.

Hierarchically structured alpha-nickel hydroxide based superhydrophobic and antibacterial coating on cellulosic materials for oil-water separation

Inspired by hierarchical surface structure of lotus leaf and insect wings, a uniform coating of disorderly oriented semi crystalline α-Ni(OH)2 nanosheets for creating dual scale (micro-nano) has been developed on cellulosic materials (cotton and wood) by a one-step facile solution process. The coating shows an innate superhydrophobic nature with a static water contact angle (SCA) ~157° and water shedding angle (WSA) ~10°. Growth pattern, morphology and microstructure, thermogravimetric mass loss behaviour and chemical bonding of α-Ni(OH)2 with commercially available cotton fabric as well as antibacterial activity of the coated fabric towards gram positive and negative bacteria have been studied systematically. For long term use as a filter cloth for oil-water separation, the coating is further modified with hexadecyltrimethoxysilane (HDTMS) restoring the hierarchical structure of α-Ni(OH)2. The dual scale surface roughness as well as low surface energy long chain HDTMS layer renders the coating a stable SCA ~162° and WSA ~8°. The superhydrophobic and superoleophilic α-Ni(OH)2-HDTMS coating shows self-cleaning ability, ~99% oil-water separation efficiency including reusability over 50 separation cycles. The coated sample also shows excellent chemical and mechanical stability as well as laundering fastness. This facile fabrication process can make an avenue for development of other transition metal hydroxides based superhydrophobic and superoleophilic coatings on cellulosic materials.

History, mass loss, structure, and dynamic behavior of the Antarctic Ice Sheet.

Antarctica contains most of Earth's fresh water stored in two large ice sheets. The more stable East Antarctic Ice Sheet is larger and older, rests on higher topography, and hides entire mountain ranges and ancient lakes. The less stable West Antarctic Ice Sheet is smaller and younger and was formed on what was once a shallow sea. Recent observations made with several independent satellite measurements demonstrate that several regions of Antarctica are losing mass, flowing faster, and retreating where ice is exposed to warm ocean waters. The Antarctic contribution to sea level rise has reached ~8 millimeters since 1992. In the future, if warming ocean waters and increased surface meltwater trigger faster ice flow, sea level rise will accelerate.

Effect of Ni addition on the arc-erosion behavior of Ag-4 wt.%SnO2 electrical contact material

To disclose the effect of Ni addition on the arc-erosion behavior of Ag-4 wt.%SnO2 contact material, the Ag-4 wt.%SnO2 contact materials with and without 4 wt%Ni were comparatively studied. The sintered materials were examined by scanning electron microscopy and transmission electron microscopy. The electrical contact tests were performed for different operations on an electrical contact testing system. The eroded morphology evolution and ingredients of the electrical contact surface under the action of arc were characterized, and the mass loss and welding behavior were studied as well. The results show that the Ag-4 wt.%SnO2 contact material has large break-arc-energy, which aggravates the SnO2 evaporation or decomposition. The reduced SnO2 content further decreases the arc erosion resistance and, in turn, causes much serious arc erosion, thereby resulting in larger mass loss and serious welding. However, for the Ag-4 wt.%SnO2-4 wt.%Ni contact material, Ni addition reduces the evaporation and decomposition of SnO2 due to its high melting point and poor thermal conductivity. Additionally, the reiterative dissolution and precipitation of Ag and Ni under the action of arc lead to the formation of fine precipitation phase, which is beneficial for the arc dispersion and generation of stable arc. As a consequence, the evaporation, splash, mass loss and welding are decreased, and the arc erosion resistance is significantly improved.

A mechanism for two-step thermal decomposition of 2,6-diamino-3,5-dinitropyrazine-1-oxide (LLM-105).

2,6-Diamino-3,5-dinitropyrazine-1-oxide (LLM-105) is a representative of the new generation of low-sensitivity energetic materials and has been applied extensively in formulations as an insensitive high-energetic ingredient. Although the initial thermal decomposition mechanism of LLM-105 has been studied based on quantum chemical calculations, the internal mechanism of the two-step thermal decomposition still lacks experimental research. Thus, this study involves a detailed experimental study to reveal the mechanism of the two-step thermal decomposition of LLM-105. The results showed that LLM-105 decay was a consecutive reaction. The first-step reaction dominated the early stage of the LLM-105 decomposition, and its products participated in the reaction of the second step. The cleavage of NO2 and NH2 groups of LLM-105 mainly occurred in the first step, while gaseous products NO and C2N2 were released during the second reaction step. The first-step reaction had a higher oxygen consumption rate and a lower carbon consumption rate, producing more heat due to more extensive oxidation of the carbon backbone. The difference in the oxidative ability and reaction rate between the two steps resulted in a two-step exothermic and mass loss behavior. This study provides further insights into the entire reaction process of LLM-105 and would be helpful for its better application and for the design of new explosives.

Wear rate at RT and 100 °C and operating temperature range of microalloyed Cu50Zr50 shape memory alloy

The effect of microalloying with Co on the wear rate and on the operating temperature range of Cu50Zr50 shape memory alloy against 304 stainless steel counterface has been investigated by studying the mass loss and wear behaviour of Cu50Zr50, Cu49.5Zr50Co0.5 and Cu49Zr50Co1 at. % at room temperature (RT) and 100 °C. For the alloys tested at 15 N, maximum wear resistance is achieved at RT for the alloy with 0.5 at. % Co compared to the parent Cu50Zr50 at. % alloy. This is mostly attributed to the effect of Co in promoting stress-induced martensitic transformation (i.e., work-hardening). For wear tests at 100 °C (100 °C plus friction temperature for 1 h), the mass loss is higher than that at RT since martensite partly reverts into soft austenite through an isothermal process. In addition, the alloys are more prone to oxidation with formation of thick oxide layers that can easily get fragmented and detached from the surface thus resulting is higher mass loss than at RT. The effect of Co in promoting martensitic transformation is negligible when testing at 100 °C, since the stress-induced martensite partly reverts into austenite and the thick oxide layer formed on the surface not only masks the effect of the underlaying substrate for it can also easily detach upon wear.