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The purpose of this study is to investigate the effect of iron content on the friction and wear performances of Cu–Fe-based friction materials under dry sliding friction and wear test condition.

Cu–Fe-based friction materials with different iron content were prepared by powder metallurgy route. The tribological properties of Cu–Fe-based friction materials against GCr15 steel balls were studied at different applied loads and sliding speeds. Meanwhile, microstructure and phases of Cu–Fe-based friction materials were investigated.

Cu–Fe-based friction materials with different iron content are suitable for specific applied load and sliding speed, respectively. Low iron content Cu–Fe-based friction material is suitable for a high load 60 N and low sliding speed 70 mm/min and high iron content Cu–Fe-based friction material will be more suitable for a high load 60 N and high sliding speed 150 mm/min. The abrasive wear is the main wear mechanism for two kinds of Cu–Fe-based friction materials.

The friction and wear properties of Cu–Fe-based friction materials with different iron content were determined at different applied loads and sliding speeds, providing a direction and theoretical basis for the future development of Cu–Fe-based friction materials.

This study aims to compare the friction and wear behaviors of Fe_68.3C_6.9Si_2.5 B_6.7P_8.8Cr_2.2Al_2.1Mo_2.5 bulk metallic glass (BMG) under sliding using dry, deionized water-lubricated and oil-lubricated conditions. The comparison was performed using a unidirectional ball-on-flat tribometer under different applied loads, and the results were compared to the properties of a conventional material, SUJ2. Fe-based BMG materials have recently been attracting a great deal of attention for prospective engineering applications.

As a part of the development of Fe-based BMGs that can be cost-effectively produced in large quantities, an Fe-based BMG Fe_68.8C_7.0Si_3.5B_5.0P_9.6 Cr_2.1Mo_2.0Al_2.0 with high glass forming ability was fabricated. In the present study, the friction and wear properties of Fe-based BMG has been comparatively evaluated under dry sliding, deionized water- and oil-lubricated conditions using a unidirectional ball-on-flat tribometer under different applied loads, and the results were compared to the properties of conventional material SUJ2.

The results show that the Fe-based BMG had better friction performance than the conventional material. Both the friction coefficient and wear mass loss increased with increasing load. The sliding wear mechanism of the BMG changed with the sliding conditions. Under dry sliding conditions, the wear scar of the Fe-based BMG was characterized by abrasive wear, plastic deformation, micro-cracks and peeling-off wear. Under water- and oil-lubricated conditions, the wear scar was mainly characterized by abrasive wear and micro-cutting.

In this investigation, the authors developed a new BMG alloy Fe_68.8C_7.0Si_3.5B_5.0P_9.6Cr_2.1Mo_2.0Al_2.0 to improve the friction and wear performance under dry sliding, deionized water- and oil- lubricated conditions.

The purpose of this study is to investigate the tribological properties of society of automotive engineers (SAE) 430B bronze-graphite composite, supplied in the form of machined and graphite embedded, used in sheet forming industry.

Pin-on-disc wear tests were performed under a constant normal load of 15 N and a sliding velocity of 60 mm/s. Due to the extended usage of Fe-based alloys in forming dies, pin materials were selected as cold work tool steel, gray and ductile irons. The weight losses of the disc (SAE 430B bronze-graphite composite) and the pins (Fe-based alloys) were measured separately under various sliding distances (5,000, 10,000 and 15,000 m). The average friction coefficients and wear tracks were obtained.

It is concluded that dry sliding behavior of SAE 430B bronze-graphite composite is the worst when operated with GGG-70 ductile iron due to its highest abrasive effect. The high hardness and nodular shape of graphite increased the abrasiveness of ductile iron. The improvement in wear resistance reached up to maximum 90 per cent and the degradation in friction coefficient was about 50 per cent by embedding graphite solids in bronze disc at dry sliding conditions.

Although the machined and graphite embedded bronze composites are indispensable parts of forming dies, there is no scientific knowledge on their dry sliding behavior.

The purpose of this paper is to produce and investigate a reliable and effective aircraft brake lining material.

In total, four different Cu‐based brake lining samples were produced by powder metallurgy. The produced samples were tested in an experimental setup on friction, wear and mechanical performance, then metallographic and scanning electron microscope inspections were performed. Hardness, compression strength and density of copper‐based brake linings were also tested. Moreover, a numerical simulation of the structural reaction of a sample under compression was carried out by using ANSYS.

According to tests, suitable aircraft brake lining material composition would be 75% Cu, 5% Fe, 5% Sn, 5% Graphite, 5% SiO₂, 5% MoS₂.

The paper will help designers choose the most proper ingredient combination for aircraft brake lining materials.

The paper notes that adding silicon dioxide and graphite forms a porosive structure. In addition, porosity brings a low strength and high wear rate.

This paper aims to investigate the effect of CaF₂ (calcium fluoride) addition as a solid lubricant on the friction and wear behaviour of sintered Fe-Cu-C materials under different loads.

In this study, the effects of CaF₂ added in varying weight percentages on the friction-wear properties of Fe-2Cu-0.8C alloys are investigated. Five Fe-2Cu-0.8C-based compositions comprising CaF₂ in 0, 3, 6, 9 and 12 Wt.% were prepared using the single-stage compaction and sintering technique. Friction coefficient, wear loss, hardness and compressive strength of the specimens were measured. The worn-out surfaces were analysed using a scanning electron microscope. Friction and wear tests were carried out on pin-on-disc machine under dry sliding conditions at room temperature.

The alloy with 3 Wt.% CaF₂ was found to be useful in improving wear and friction properties, whereas higher contents of CaF₂ resulted in increased wear and friction. Apart from enhanced tribological properties, a slight decrease in the compressive strength was also observed in the 3-Wt.%-CaF₂-added sample. Adhesion and abrasion were the prominent wear types observed during this study.

A new self-lubricating composite is developed where CaF₂ is used as a solid lubricant in a Fe-Cu-C-based matrix. CaF₂, being a high-temperature lubricant, is tried and tested for friction and wear at room temperature, and the results show that the addition of CaF₂ in Fe-Cu-C improved its friction and wear properties. Thus, the developed material can be used for antifriction applications.

This paper aims to obtain high mechanical strength and good self-lubricating property of iron-based powder metallurgy materials. A new type of bilayer material with dense substrate and porous surface was proposed in this paper to obtain high strength and good self-lubricating property.

The materials were prepared by powder metallurgy. Their friction and wear properties were investigated with an end-face tribo-tester. Energy dispersive spectrometer, X-ray diffraction and the 3D laser scanning technologies were used to characterise the tribological properties of materials. The tribological and bearing mechanisms of the monolayer and bilayer materials were compared.

The results show that adding proper TiH₂ can effectively improve the porosity and hardness. With the TiH₂ content increased from 0 to 4 per cent, the average friction coefficients increase slowly, and the wearability decreases first and then increases. When containing 3.5 per cent TiH₂, high strength and good self-lubrication characteristics are obtained. Besides, the tribological properties of monolayer materials are better than those of bilayer materials when the load is between 980 and 1,470 N, while the opposite result is obtained under the load varied from 1,470 to 2,450 N. In the bilayer material, the porous oil surface can lubricate well and the dense substrate can improve the mechanical property. So, its comprehensive tribological and mechanical properties are better than those of monolayer material.

The friction and wear properties of a new type bilayer materials were investigated. And their tribological mechanisms were proposed. This work can provide a theoretical reference for developing high-performance iron-based oil materials under boundary lubrication.

This paper aims to consolidate the results of various researchers focusing the different applications, so that this paper could become the torch bearer for the futuristic researchers working in the domain of cold gas dynamics spray coating.

A study on the cold spray coating is presented by summarizing the data present in literature. Important factors such as coating temperature, pressure, coating thickness, particle size, which affect the erosion-corrosion (E-C) resistance, physical and mechanical properties of boiler steel are stated. This paper also addresses the use of cold spray coating and compares it with other different thermal spray processes.

From the literature review, it was noticed that cold spray technology is best as compare to other thermal spray processes to reduce porosity, increase hardness, adhesion strength and retention in properties of feedstock powders.

Cold spray coating technology has a great potential in almost every field especially in restoration of surfaces, generation of complex surface, biomedical application, resist hot corrosion, wear, oxidation and erosion corrosion.

This paper aims to verify weather atmospheric plasma spray (APS) in situ remelting posttreatment is effective for densifying the porous FeCoCrMoCBY amorphous alloy (FAA) coating and improving the antiabrasion and anticorrosion performances or not.

APS was used to deposit and in situ densify FAA coating on the 40Cr substrate. Scanning electron microscope, X-ray diffractometer, energy dispersive spectroscopy, neutral salt spray, hardness and wear behavior test were used to evaluate the densifying effects.

APS remelting technology can effectively improve the hardness of the coating by reducing the porosity. After remelting at 30 kW power, the hardness of the coating increased by about 260 HV0.2 and the porosity decreased to 2.78%. The amorphous content of the coating is 93.9%, which is about 3.5% lower than original powders. The electrochemical impedance spectrum and neutral salt spray test results show that APS remelting can reduce the corrosion rate by about 62.7%.

APS remelting method is firstly proposed in this work to replace laser remelting or laser cladding methods. APS remelting method can effectively improve the corrosion and abrasion resistance of the FAA coating by increasing the densification with much low recrystallization, which is big progress for application of FAA coatings.

The deposition of particles onto a substrate during the cold spraying (CS) process relies on severe plastic deformation, so there are various micro-defects induced by insufficient deformation and severe crushing. To solve the problems, many post-treat techniques have been used to improving the quality by eliminating the micro-defects. This paper aims to help scholars and engineers in this field a better and systematic understand of CS technology by summarizing the post-treatment technologies that have been investigated recently years.

This review summarizes the types of micro-defects and introduces the effect of micro-defects on the properties of CS coating/additive manufactured, illustrates the post-treatment technologies and its effect on the microstructure and performances, and finally outlooks the future development trends of post-treatments for CS.

There are significant discoveries in post-treatment technology to change the performance of cold spray deposits. There are also many limitations for post-treatment methods, including improved performance and limitations of use. Thus, there is still a strong requirement for further improvement. Hybrid post-treatment may be a more ideal method, as it can eliminate more defects than a single method. The proposed ultrasonic impact treatment could be an alternative method, as it can densify and flatten the CS deposits.

It is the first time to reveal the influence factors on the performances of CS deposits from the perspective of microdefects, and proposed corresponding well targeted post-treatment methods, which is more instructive for improving the performances of CS deposits.

This paper aims to discuss that a WC/Co-Cr alloy coating was applied to the surface of H13 steel by laser cladding.

The oxidation behavior of the WC/Co-Cr alloy coating at 600°C was investigated by comparing it with the performance of the steel substrate to better understand the thermal stability of H13 steel.

The results showed that the WC/Co-Cr alloy coating exhibited better high-temperature oxidation resistance and thermal stability than did uncoated H13 steel. The coated H13 steel had a lower mass gain rate and higher microhardness than did the substrate after different oxidation times.

The WC/Co-Cr alloy coating was composed of e-Co, CW3, Co6W6C, Cr23C6 and Cr7C3; this mixture offered good thermal stability and better high-temperature oxidation resistance.