Friction Wear Testing Research Articles

Effect of Mo on wear resistance of Stellite31 cladding layer

Stellite alloys are a kind of cobalt-based alloys, which have excellent properties and are widely used in numerous areas. However, the wear resistance of Stellite alloys is poor at room temperature. In this study, Stellite31 cladding layers added with 0%, 1%, 2% and 3% of Mo(wt-%) were prepared by laser cladding. The grain sizes were measured by scanning electron microscope images, the distributions of Mo were analysed by energy dispersive X-ray spectrometry, the physical phase compositions were analysed by X-ray diffractometer, and the wear resistance was evaluated by reciprocating friction wear tester and wet sand wear testing machine. The results showed that the grain sizes of the cladding layers decreased with the increase of Mo content, the wear loss of the cladding layers became lower and the friction coefficient decreased under the same test conditions. It was concluded that increasing the Mo content could improve the wear resistance of the Stellite31 cladding layer at room temperature.

The Effect of Laser-Cladded Co6, T400, and Ni-Based 30WC Coatings on the Wear Resistance of H13 Steel

To enhance the wear resistance of H13 steel (4Cr5MoSiV1), Co6, T400, and Ni-based 30WC coatings were applied to the surface of H13 steel using laser cladding technology. The microstructures and phase compositions of the three coating types were analyzed using SEM and XRD methods. The high-temperature friction and wear performance of the three coated samples and H13 steel were measured through high-temperature friction wear tests, and the friction wear types of the four samples were analyzed. A comparative analysis of experimental data led to the following conclusions: (1) Among the four samples, the Ni-based 30WC-coated sample exhibited the best self-lubricating properties. (2) The average wear area of H13 steel was 0.059 mm2, and the wear volume was 0.29 mm3; the average wear area of Co6-coated samples was 0.050 mm2, and the wear volume was 0.25 mm3; the average wear area of T400-coated samples was 0.002 mm2, and the wear volume was 0.01 mm3; and the average wear area of the Ni-based 30WC-coated sample was 0.035 mm2, and the wear volume was 0.17 mm3. In terms of wear resistance, the ranking from highest to lowest was: T400-coated sample > Ni-based 30WC-coated sample > Co6-coated sample > H13 steel. (3) Based on the classification of friction wear types, H13 steel primarily exhibited adhesive wear and oxidized wear; the Co6- and T400-coated samples primarily showed adhesive wear, abrasive wear and oxidized wear; and the Ni-based 30WC-coated sample mainly exhibited abrasive wear and oxidized wear.

Microstructural evolution and tribological properties of TC6 titanium alloy strengthened by laser peening combined with nitrogen ion implantation

To obtain a combined strengthening layer and further redouble the ability to resist wear of TC6 titanium alloy, an innovative technique of laser peening plus nitrogen ion implantation was proposed. The tribological properties of the specimen subjected to combined laser peening and nitrogen ion implantation were analyzed using transmission electron microscope, nanoindentation tester, sliding friction wear tester and scanning electron microscopy. The results showed that laser peening combined with nitrogen ion implantation induced a higher density of dislocation than that produced only by laser peening or nitrogen ion implantation. Compared with the ion implanted and laser peened samples, the surface nano-hardness subjected to combined strengthening process was increased by 21.3 % and 5.8 %. Moreover, the friction coefficient of combined processed specimen reduced to 0.4, the wear tracks depth and width were about 19.02 μm and 300 μm, while the wear mechanism was mainly abrasive and oxidative wear. The dislocations, sub-grains and mechanical twins produced by laser peening provided large amounts of diffusion channels for ion implantation, which conferred better wear resistance than the samples processed only by laser peening or nitrogen ion implantation.

Wear Properties of Metal Material in Dredging Equipment

In dredging engineering, the parts of dredging and conveying system which contact with dredging mixture often suffer from serious wear and short service life. In order to improve the durability of materials, new materials and generation processes are constantly proposed. It is always a difficult work to analyze the wear properties and mechanism of materials.In this paper, dry friction and abrasive wear tests were carried out on Cr15, Cr26, Fedur®40, medium manganese steel and XGG with Q235 carbon steel as the comparison material. The wear mechanism of materials was analyzed by scanning electron microscope (SEM) observation on the wear surface of materials. Under the test conditions, the dry friction wear rates of the five materials were 6.98×10−6 mm3/Nm,5.71×10−6 mm3/Nm,20.2×10−6 mm3/Nm,21.9×10−6 mm3/Nm and 5.39×10−6 mm3/Nm respectively.The wear rates of abrasive wear tests were 58.3×10−6 mm3/Nm,25.2×10−6 mm3/Nm,83.4×10−6 mm3/Nm,30.9×10−6 mm3/Nm and 32.1×10−6 mm3/Nm respectively. The results show that the metal surface is covered with coarse and deep cutting and chipping marks under abrasive wear, while the metal surface only has fine furrowing and a little fatigue spalling under dry friction wear. The wear rate of abrasive wear of five wear-resistant materials is much higher than that of dry friction wear. Cr26 and XGG showed better wear performance than other materials under the two test conditions.

Evaluation of the Mechanical and Tribological Behavior of Polyether Ether Ketone Fiber-Reinforced Resin-Based Friction Materials Fabricated by Wet Granulation.

Resin-based friction materials (RBFMs) strengthened by polyether ether ketone (PEEK) fiber were designed and prepared in this study. Specimens incorporating PEEK fiber of 2-8 wt.% were fabricated based on wet granulation, and then the effects of the PEEK fiber content on the mechanical and tribological properties of RBFMs were systematically investigated. The results showed that PEEK fiber can sense the braking temperature and then effectively regulate the comprehensive properties of RBFMs. The specimen incorporating 6 wt.% PEEK fiber obtained the optimal comprehensive performance with a stable friction coefficient (COF), excellent fade resistance and recovery properties, and better wear resistance. The worn surface was inspected using a scanning electron microscope. After the friction-wear test, the specimen with 6 wt.% PEEK fiber presented a number of primary and secondary plateaus and a reduced number of pits with wear debris on the worn surface. The study indicated that PEEK fiber could not only enhance the mechanical and tribological properties of RBFMs at low temperatures because of their high strength and self-lubrication but also adhere to wear debris to reduce abrasive wear at high temperatures; furthermore, the adhered wear debris could form a secondary plateau under normal pressure, which could alleviate abrasion.

Modelling of tribological behavior and wear for micro-textured surfaces of Ti2AlNb intermetallic compounds machined with multi-dimensional ultrasonic vibration assistance

Employing multi-dimensional ultrasonic vibration machining (MDUVM), Ti2AlNb intermetallic compounds were processed to generate highly consistent and uniformly arranged micro-texture surfaces. Compared to conventional machining (CM) surfaces, MDUVM surfaces exhibited a noticeable 10.9 % increase in hardness. Sphere-on-disk friction wear tests indicated a noteworthy 15 % reduction in both friction force and coefficient on MDUVM surfaces. The MDUVM surfaces improved contact pressure distribution, reduced oxidation, and facilitated smoother wear debris transition within the wear zone. As a result, the spread of wear into deeper layers was effectively inhibited. An Archard-based predictive model was developed to quantitatively predict wear behavior by incorporating surface micro-texture, confirming the significant influence of surface morphology on frictional wear, which was consistent with experimental findings.

Effect of in situ synthesis reaction of methacrylic acid (MAA)/zinc oxide (ZnO) on frictional wear of metals during compounding

During prolonged operation, the end face of the internal mixer, a crucial component in rubber processing, experiences wear, resulting in an increased gap between the mixing chamber and the end face. This gap can lead to material leakage and reduced mixing efficiency, negatively impacting rubber properties. To address this issue, researchers have introduced dynamic covalent bonds into the molecular rubber chains, giving the material self-healing properties. This advancement is essential for extending rubber lifespan and reducing production costs. One common approach involves adding methacrylic acid (MAA) and excess zinc oxide (ZnO) to create ionic crosslinking networks, limiting covalent crosslinking and enabling in-situ polymerization of MAA/ZnO, resulting in self-healing capabilities. However, the strong acidity and corrosive nature of MAA can cause metal wear. In our study, we mechanically blend MAA with ZnO to produce zinc methacrylate (ZDMA)/rubber composites. We investigate the in-situ synthesis mechanism of MAA and ZnO and assess the impact of MAA on the friction and wear of the internal mixer's end face. Our findings reveal that ZDMA ion pairs form an “ion cross-linked network” within the rubber chain, hindering SiO2 particle dispersion and increasing aggregation within the rubber matrix. This compromises dispersion and leads to abrasive wear from SiO2 particles, corrosive wear from high-temperature water vapor, and corrosive wear from MAA. Additionally, excessive ZDMA self-polymerization alters SiO2 particle agglomerates. The strong acidity of MAA and the “ion cross-linked network” within the rubber matrix significantly affect SiO2 particle dispersion, friction coefficients, metal surface roughness, and metal wear. Our comprehensive analysis, including SEM, dispersion, RPA, metal surface morphology, and CSM friction wear tests, identifies the optimal cross-linking effect with the addition of 15 phr of MAA, resulting in a well-defined “ion cross-linked network” within the rubber matrix, enhancing rubber performance. However, SiO2 particle dispersion is compromised, leading to increased agglomeration and heightened metal wear.

Development of multifunctional current-carrying friction and wear test machine based on LabVIEW

In order to study the effect of friction wear behavior on electrical signal transmission, a carrier friction wear test machine was developed which can be analyzed under different test conditions (load, speed and current). The testing machine builds a measurement and control system through LabVIEW platform to realize real-time acquisition and synchronous display of electrical signals, friction coefficient and temperature, and control of load size, and uses wavelet decomposition and arithmetic average to process data and PID control algorithm to revise load in real time. The experimental results show that the stability of the test machine and the accuracy of control system meet the test requirements.

Liquid-assisted femtosecond laser-induced LIPSS on the surface of YT15 cemented carbide and its mechanical properties

To enhance the mechanical performance of precision mechanical components such as grinding spindle and precision bearings, and to minimize the adverse effects of laser processing, we utilized femtosecond laser irradiation on the surface of YT15 cemented carbide in both air and liquid environments. This process induced various morphologies of LIPSS structures, and we subsequently examined the impact of these LIPSS structures on the mechanical properties of the cemented carbide surface to the greatest extent possible. Surface morphology was characterized using field emission scanning electron microscopy and a morphology profiling system. It was observed that, compared to the air medium, femtosecond laser radiation in a liquid medium could induce larger areas of LIPSS. The Marangoni effect drove the growth of LIPSS structures, and the number of laser processing cycles and laser power had an impact on the morphology of LIPSS. Surface residual stress after laser energy impact was measured using X-Red, and surface microhardness in the laser-affected region was determined using a microhardness tester. The results indicated that laser energy impact generated residual compressive stress on the surface and refined the grain structure, contributing to increased surface microhardness. Simultaneously, SS304 was used as the friction counterpart to conduct friction-wear tests in directions parallel and perpendicular to the LIPSS. Fluid lubrication simulations were also performed. It was observed that LIPSS had a certain beneficial effect on the friction characteristics of the material surface.

Effect of laser energy densities on the phase composition change in laser-cladded AlCoCrNbMo high-entropy alloy coatings

This work designed a new high-entropy alloy (HEA), namely, AlCoCrNbMo, and prepared it by using laser cladding (LC). The effects of different values of laser energy density (Es) on the phase composition, microstructure, mechanical properties and corrosion resistance of the HEA coating were investigated via X-ray diffractometry; scanning electron microscopy; energy dispersive spectrometry and microhardness, friction wear and electrochemical tests. Results indicate that increasing Es (Es = 35, 55, 75 J/mm2) leads to the formation of different phases, including bcc1, bcc1 +bcc2 and bcc1 +bcc2 +Al3Nb, in the coating. The bcc1 phase is rich in Co and Cr elements, whereas the bcc2 phase is rich in Nb and Mo elements. As Es increases, the HEA coating shows increasing hardness and wear resistance but decreasing corrosion resistance. Moreover, the AlCoCrNbMo alloy prepared through vacuum arc melting does not conform to the form of HEAs but is instead composed of various intermetallic compounds, reflecting the unique advantage of LC. This paper discusses the influence of LC process parameters on the microstructure of HEAs and the unique advantages of LC for HEA preparation.

Microstructure and properties of coarse WC-10CoCrFeMnNi cemented carbide by mechanical alloying and hot pressing sintering

WC-10CoCrFeMnNi coarse cemented carbide was made by hot pressing sintering at temperatures of 1000 ℃, 1100 ℃, 1200 ℃, and 1300 ℃, respectively. Using powders of the high entropy alloy (HEA) CoCrFeMnNi that have been mechanically alloyed (MA). Through the use of X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, electron backscatter diffraction, Vickers microhardness testing, transverse rupture strength testing, and friction wear testing, the microstructure and general properties of coarse WC-HEA cemented carbide were investigated. With hardness, fracture toughness, transverse rupture strength, and coefficient of friction of 1206 HV30, 9.34 Mpa.m1/2, 1222 Mpa, and 0.595, respectively, WC-10CoCrFeMnNi cemented carbide exhibits the best combination of properties. By examining the experimental data, it was possible to produce the WC-10CoCrFeMnNi cemented carbide at 1100 °C with good overall performance. According to the excellent performance of WC-HEA in fracture toughness, it becomes possible as a new type of cemented carbide.

In Situ Synthesis of Graphene Oxide-Sealed LDHs Coatings: A Novel Approach to Enhancing Corrosion Resistance and Tribological Performance on Magnesium Alloys

This study introduces an innovative approach to enhancing the corrosion resistance and tribological performance of magnesium alloys by in situ growing zinc-aluminum layered double hydroxide (ZnAl-LDHs) with graphene oxide (GO) sealing. Traditional LDHs coatings exhibit limitations in corrosion protection due to their porous structure. This paper advances the LDHs coating technology by integrating GO, forming a composite LDHs/GO coating on magnesium alloys. The novel incorporation of GO provides a unique two-layered defense system against corrosion: the GO layer serves as a high-resistance barrier to corrosive agents, while the LDHs layer absorbs NO3− ions, offering a secondary protection. The coating’s properties were meticulously characterized using techniques such as scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier-transform infrared (FTIR) Raman spectroscopy, electrochemical assays, and friction-wear tests. Experimental findings reveal that the synergistic action between LDHs and GO results in significant improvements in corrosion resistance and friction reduction. Specifically, GO’s adherence to the LDHs coating’s pores and its ability to transfer into the friction layer during wear significantly enhances the coating’s integrity and stability. The successful in situ synthesis of LDHs /GO coatings opens new horizons for composite coatings, with potential implications across various industrial applications.

Study on Hydrodynamic Lubrication and Friction Reduction Performance of Cylindrical Rolls With Tesla Valve Texture

Friction and wear seriously affect the efficiency and life of a machine device. The dynamic pressure lubrication and friction properties of the surface are improved by surface texture technology, which plays an extremely important role in reducing friction and wear. In order to maximize the hydrodynamic lubrication and friction reduction performance of surface texture, a Tesla valve surface texture is proposed in this article. The oil film bearing capacity and wall friction of Tesla valve texture are examined through computational fluid dynamics fluid simulation. Cylindrical rolls with Tesla valve texture are prepared by using laser processing technology, and comparative friction wear tests are conducted. The results show that the lubrication performance of Tesla valve texture is four times higher than without this texture. The friction coefficient and wear loss of the cylindrical rolls with Tesla valve texture are, respectively, 39.7% and 66.7% lower than those of the cylindrical rolls without texture. Tesla valve texture effectively improves the dynamic pressure lubrication and friction in the cylindrical rolls.

Performance of Ni–SiC composites deposited using magnetic-field-assisted electrodeposition under different magnetic-field directions

To improve the surface and structure performances of metal parts, magnetic-field-assisted electrodeposition was applied to deposit the Ni-SiC composites on Q235 steel substrates. The surface morphology, roughness, microstructure, abrasion resistance, and corrosion resistance of the composites were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray diffraction (XRD), hardness and friction wear tests, and electrochemical analysis, respectively. The Ni-SiC composite (MC-1) fabricated at 0.5 T with perpendicular magnetic direction exhibited a smooth, dense, and fine surface morphology, the highest SiC content, and a Ni grain size of only 72.3 nm. Furthermore, AFM images showed that the roughness of the MC-1 composite (Ra of 84 nm) was lower than those of Ni-SiC composites deposited at 0 T and 0.5 T. XRD analysis indicated that the application of a perpendicular magnetic field changed the preferred growth of Ni grains from the (200) to (111) crystal plane. MC-1 had the highest microhardness and lowest friction coefficient of all composites, indicating its superior abrasion resistance. Furthermore, the MC-1 composite had the lowest corrosion current (0.466 μA/cm2) and highest corrosion potential (−254 mV), indicating its superior corrosion resistance compared to the other composites.

Experimental and temperature field simulation study of Inconel 718 surface cladding based on vacuum electron beam heat source

By vacuum electron beam welding machine based on simulation of temperature field of NiCrBSi, experiment was conducted by vacuum electron beam surface cladding (VEBSC). The microstructure and friction wear properties of the specimens were analyzed by scanning electron microscope (SEM), electron backscatter diffractometer (EBSD), microhardness tester and friction wear tester under different welding beam currents (IW), respectively. The results show that the grain orientation in Inconel 718 in the rolled state is very dispersed and consists of equiaxed austenite grains (about 15 μm) with a high number of annealed twins. The internal orientation difference becomes relatively uniform after VEBSC, and a large number of elongated needle-like grains (about 200–300 μm) appear in the surface layer. At the same time, the low angle grain boundary of the clad layer (CL) of the specimen increases and then decreases with the increase of IW. When IW = 18 mA, the specimen surface hardness reaches a maximum value of 632.5 HV, and the friction coefficient is at least 0.25. The wear mechanism after cladding is dominated by plowing and abrasive wear to improve the wear resistance of the material. However, the high temperature oxidizing properties do not change much.

Investigations of the mechanical and high-temperature tribological properties of the Inconel 718 alloy formed by selective laser melting

Selective laser melting (SLM) is a 3D printing technology suitable for manufacturing high-precision metal parts with complex geometries. At present, the research on SLM technology to produce high performance, complex structures made of superalloy parts has become the focus of aerospace and other fields. In this work, the microstructure, microhardness, and tensile strength of an Inconel 718 superalloy synthesized using SLM technology were first investigated. Then, the wear characteristics of the alloy at various temperatures were examined by multifunctional friction and wear testing equipment. Finally, a thorough analysis of the wear damage mechanisms of the materials over a wide temperature range was performed. The grains of the Inconel 718 superalloy formed by SLM developed as columnar grains that were more evenly and firmly dispersed along the horizontal axis. The material had a slightly greater microhardness in the vertical plane (HV1 =346) than in the horizontal plane (HV1 =324). A tensile test revealed that the horizontal tensile strength of SLM-formed Inconel 718 alloy was 50.1 MPa higher than that in the vertical direction, while the elongation was 0.14 % lower than the latter. The fracture mechanism of the material presented a fracture type dominated by microporous aggregation. A friction wear test showed that the friction wear coefficient of the SLM-formed Inconel 718 alloy gradually decreased with temperature. Abrasive wear, oxidative wear, and adhesive wear were the main wear mechanisms for the material during wear testing in the high temperature environments. The wear surface of the alloy material generated an oxide layer at 650 °C, which was effective in lowering friction and wear.

An attempt towards green machining of Ni-based Hastelloy C4 alloy: Effect of vegetable oils and their combination with TiO2 and SiO2 nanoparticles on outputs

The importance of nickel-based superalloys has increased day by day due to their use in special applications. However, the difficulties in the machinability of these alloys bring some concerns about parts quality and efficiency. Although researchers have tried ways (such as the use of high-performance cutting fluids) to overcome these challenges, their sustainability is still controversial. Therefore, this experimental research aims to contribute to the sustainable machining of nickel-based superalloys. In this regard, the present study investigates the effectiveness of vegetable-based fluids (sunflower, olive, hazelnut, and corn oils) and nanofluids (SiO2 + sunflower oil, SiO2 + olive oil, SiO2 + hazelnut oil, SiO2 + corn oil, TiO2 + sunflower oil, TiO2 + olive oil, TiO2 + hazelnut oil, and TiO2 + corn oil) during the machining of Ni-based Hastelloy C4 alloy. The study was carried out in three stages. In the first stage, all cutting fluids' pH and thermal conductivity values were measured. In the second stage, machinability tests were conducted under the prepared cutting fluids. Later, friction-wear tests of the cutting fluids that offered the best performance in the previous stage were done. As a result, the pH change was significantly increased with the addition of nanoparticles (TiO2 and SiO2) to corn oil. TiO2 nanoparticles allowed further improvement of thermal conductivity. Compared to dry machining, improvements of 58.57%, 34.88%, 53.18%, and 36.1% in surface roughness, cutting temperature, tool wear, and power consumption were achieved with corn oil+TiO2 nanofluid, respectively. It was determined that adhesion, BUE, BUL, and chipping were dominant damage types. Also, an adhesive is the dominant wear mechanism.

Preparation of durable superhydrophobic composite surface

Surface durability deficit is the most serious challenge confronting superhydrophobic surfaces. The creation of durable superhydrophobic surfaces is therefore of significant importance. In this study, we etched the surface of 1060 aluminum alloy coated with polydimethylsiloxane and nano-fumed silica (PDMS&NF-SiO2) using an infrared nanosecond laser to yield a durable superhydrophobic hybrid surface (SHS). We characterized the composite surface’s static water contact angle (WCA), water roll-off angle (WSA), morphology, and composition using a contact angle meter, scanning electron microscope (SEM), three-dimensional profilometer, energy-dispersive spectrometer (EDS), and Fourier-transform infrared spectroscopy (FT-IR). We also conducted tests for the mechanical durability and thermal stability of the SHS surface using tape peeling, steel wool friction wear, blade scraping, sand impact, and heat treatment. Results indicated that the WCA and WSA of the SHS surface were 158.1° and 6.2°, respectively. The SHS surface maintained its superhydrophobic properties after withstanding at least 150 tape peeling tests, 100 steel wool friction wear tests, 50 blade scraping tests, and a 450 g sand impact test, demonstrating exceptional mechanical durability. The surface WCA and WSA of the SHS after a 30-hour heat treatment at 100 ℃−300 ℃ were 157.4° and 7.6°, respectively, demonstrating good thermal stability. We believe that this study's design and fabrication of superhydrophobic composite surfaces offer new insights for the preparation of wear-resistant and high-temperature resistant superhydrophobic surfaces.

Corrosion wear behavior of 30CrNi2MoVA steel in simulated seawater

This study investigates the corrosion wear behavior of 30CrNi2MoVA steel in a simulated seawater environment using an electrochemical workstation and a friction-wear testing machine. The results indicate that under dry friction conditions, an increase in load leads to an increase in friction coefficient and wear depth. In seawater, an increase in speed results in a decrease in friction coefficient and an increase in wear depth, while the effect of load on material loss is minimal, highlighting the crucial role of speed in corrosion-wear behavior. The synergistic effect of corrosion and wear causes more severe damage than dry friction. The corrosion wear behavior of 30CrNi2MoVA steel is a dynamic process of “mechanical deoxidation-chemical reoxidation,” as evidenced by the change in corrosion potential from −0.6502 V to −0.8646 V and increased material loss.

Exploring the role of indium on the microstructure evolution and interface bonding behavior of brazing diamond abrasive with modified Cu–Sn–Ti

In the brazed joints prepared by Cu-Sn-Ti filler metal, it was found that the filler metal has poor wettability to diamond and diamond abrasive grits are prone to uneven wear resulting in low efficiency of diamond tools and difficulty in achieving the expected processing which are the key factors restricting the performance of brazed diamond tools with Cu based filler. This study aims to improve the wettability of Cu-Sn-Ti filler metal and the brazed joint wear resistance. For this purpose, a new Cu-Sn-Ti-Ga-In composite filler metal was proposed. In this experiment, the subcooling degree and microstructure morphology of the new filler metal were investigated, the microhardness and shear strength of the filler metal were determined, and the shear fracture morphology was analyzed. Wetting tests were conducted on graphite plates to study the effect of indium elements on the wettability of the filler metals. Brazed joints were also prepared, and the crawling morphology of the filler metal on the diamond surface and the wear marks of the diamond abrasive after the frictional wear test were observed. The test results show that Sn3Ti5 is a solid solution is favorable to explain some phenomena. The indium element can increase the subcooling of the filler metal, thus promoting the refinement of Sn3Ti5, and the formation of eutectic microstructure. In brazed joints, indium increases the wettability of the filler metal on the diamond surface thus increasing the climb height and reducing the uneven wear rate, and the brazed joints have the best cutting performance when the filler metal is added with 1 wt% of indium element.