Wear Performance of Cu–Cd, Cu–Be and Cu–Cr–Zr Spot Welding Electrode Materials

Abstract

Heating of the electrode at the work–piece interface zone in spot welding, leading to degradation of the tip, becomes a significant concern in the high-volume production automotive industry. By recognizing the interrelationship between hardness, wear resistance, and thermal conductivity, the authors emphasize the importance of selecting electrode materials with suitable alloying elements desirable for achieving optimal performance in spot welding applications. This paper studies the wear behaviour of three types of spot-welding electrode materials under dry sliding contact conditions. A pin-on-disc tester was used to investigate Cu–Cd, Cu–Be and Cu–Cr–Zr alloys’ wear behaviour under variable parametric load, temperature and time conditions. Taguchi L9 orthogonal array was used to investigate the significance of parameters and their effect on linear wear. The ranking of the parameters was performed using SN ratio analysis. The wear mechanism was also studied using SEM analysis. Abrasive wear was observed at lower loads, while adhesion, oxidation and plastic deformation were observed under high-load and -temperature conditions. This study suggests an alternative to the presently used electrolytic tough pitch (ETP) Cu electrode involving equally good wear-resistance material. However, a detailed investigation on the effect of plasma on the metallurgical characteristics of selected material is suggested.

1. Introduction

Because of the high production volume in the automotive industry, resistance spot welding has a relatively short lifespan for its electrodes, which has been a significant source of concern. The weld nugget is created by controlling the time and pressure during the welding process and using a high amount of current to generate heat. Because of the extreme heat generated at the interface between the electrode and the workpiece, there is a variation in the temperature of the interface, the current density, and the reduced hardness. This, in turn, causes an excessive amount of electrode wear and poor weld quality [1]. As a direct result of the severe pitting and ploughing that takes place at the surface of the welding electrode, rapid electrode deprivation takes place.

A perfect electrode material for resistance spot welding would have high thermal and electrical conductivity, sufficient strength to resist deformation under pressure and temperature, and a low coefficient of thermal expansion because of the pressure applied. During the application of RSW to high-ductile pure Cu, deformation of the tooltip occurs, which changes current density and affects weld quality. Pure copper has high thermal and electrical conductivity; however, it has very low hardness and annealing temperature, leading to faster degradation of the electrode material. Wherever there is the possibility of mechanical contact, wear resistance is an essential property of the material, and it must be improved if the material is to have high longevity. Cu alloys are the material of choice for electrodes because they solve several issues, including the limited lifespan of the electrodes and their inconsistent weld quality. Electrode life is also dependent on the types of metals that are being welded, the thickness of the sheet metal, the tribological characteristics of the base metal, as well as welding process parameters such as current, time, force, and surface roughness at the contact tip [2,3,4]. An investigation was conducted into the surface asperities and oxides that formed on electrical contact resistance [5] discovered that the effect of the oxide layer is more dominant than the initial surface roughness and causes more pitting of the material that makes up the electrode. The authors, Bachchhav et al., used the analytical hierarchy process (AHP) to rank the material properties of spot-welding electrodes. They discovered that high electrical conductivity, thermal conductivity, and wear resistance are the most predominant properties out of the 10 characteristics considered [6]. However, conducting this analysis using a single material presents several challenging obstacles. The rise in temperature, the sliding velocities, and the contact pressure on sliding interfaces are all factors that influence the amount of wear [7,8]. Researchers led by Yuan and his colleagues investigated the wear patterns of high-strength and high-conductivity copper alloys by using a block-on-ring wear tester to simulate dry sliding contacts [9]. Several types of wear were observed, including abrasion, adhesion, oxidation, and plastic deformation. When the sliding speed and load are lower, the oxide layer that causes abrasive wear can be seen; however, when the load and sliding speed are increased, adhesive wear can be seen to a much greater extent. The resistance spot welding of aluminium alloys was analyzed in detail by Manladan et al. They observed that the oxide layer reduces the conductivity at the interface between the electrode and the work. This results in a higher current being drawn and more heat being generated at the interface, leading to rapid electrode tip wear [10].

The effect of electrical current on the tribological behaviour of copper alloys, the use of composite materials, the use of different processing techniques such as extrusion, powder metallurgy, high-pressure torsion, and the use of different types of coatings have all been studied as possible ways to improve weld quality and electrode life [11,12,13,14,15]. These studies have led to different attempts to improve welding quality and electrode life. An evaluation was conducted to determine the effect of Ti concentration on the friction and wear behaviour of Cu–Ti alloys under dry sliding contact [16]. It has been observed that an increasing concentration of Ti has a significant impact on lowering the amount of friction and wear that occurs. Additionally, titanium’s grain distribution significantly impacts the control of wear [16]. The dry sliding wear behaviour of Ti-6Al-4V titanium alloy against EN31 and wear debris analysis were studied, and the results showed that the amount of wear increased as the load increased [17]. According to Mashahito and colleagues’ research on the tribological properties of chromium copper alloys and beryllium copper alloys [18], high thermal conductivity indicates favourable tribological properties.

The tribological behavior of commercially pure copper (Cu 99.9%) in contact with a graphitic material was analyzed with two distinct microstructures: a coarse-grained microstructure with an average grain size of 20–60 μm, which was achieved through annealing, and a submicrocrystalline microstructure with an average grain size of 0.22 μm, which was obtained via severe plastic deformation. The results indicate that the annealed submicrocrystalline samples exhibit friction coefficients that are 12–20% lower compared than that of the annealed coarse-grained (CG) sample [19]. Aksenov et al. unveils the findings from research conducted on a popular alloy system, Cu–Cr–Zr, in its ultrafine-grained state. The alloy was further enhanced by the addition of cadmium (0.2% by weight) with the aim of augmenting its physical, mechanical, and operational properties, while also addressing environmental safety concerns. The newly developed alloy system exhibits excellent thermal stability at 400 °C, surpassing the thermal stability of cadmium bronzes by a factor of two. Additionally, this alloy system demonstrates significantly improved wear resistance compared to the existing Cu alloys [20,21].

The structural changes that occurred during plastic deformation of a Cu-0.3%Cr-0.5%Zr alloy were subjected to multidirectional forging and (or) cold rolling were studied. It was found that the formation of ultrafine grains is closely associated with the development of geometrically necessary boundaries, which can be attributed to deformation banding [22,23]. To achieve exceptional mechanical and functional properties in Cu–Cr–Zr alloys, a combination of aging treatment with large plastic deformation facilitates the formation of an ultrafine-grained microstructure, characterized by a high dislocation density, which leads to substantial strengthening of the material [24]. Through enhanced thermo-plastic treatment methods, it is possible to achieve a more favourable compromise between the electrical conductivity and hardness of the Cu–Cr–Zr alloy. By refining the treatment processes, it becomes feasible to improve both the electrical conductivity and hardness simultaneously, thereby optimizing the overall performance of the alloy [25,26,27]. The hardness, electrical conductivity and tribological behaviour of the Cu alloys can be significantly enhanced through high-pressure aging treatment [28,29].

The dry sliding friction and wear behavior of the Cu–Cr–Zr alloy were examined at elevated temperatures. The investigation involved sliding the alloy against a ceramic ball and using a pin-on-disc setup to analyze the thermal friction behavior across various temperature ranges. The coefficient of friction demonstrated an initial increase at 100 °C, followed by a subsequent decrease. Conversely, the wear rate exhibited a significant rise with increasing temperatures [30]. The impact of cadmium addition on the microstructure and wear behavior of the Al-12%Si alloy was investigated under dry sliding conditions. The findings revealed that the inclusion of cadmium in the Al–Si matrix resulted in a reduction in wear rate and improved wear properties, particularly for alloys containing cadmium. This can be attributed to the presence of cadmium phase in the form of cuboids or hard particles dispersed within the eutectic matrix. These cadmium particles contribute to a decrease in the friction coefficient, particularly under high loads [31]. Straffelini et al., examined the tribological behavior of Cu–Be alloys under dry sliding conditions using an AISI M2 steel counter-face. As the applied load was increased, a transition in the wear mechanism was observed, shifting from metallic wear to tribo-oxidative wear. During sliding, the formation of a tribological layer was observed on the surface of the Cu–Be specimens. This layer is believed to play a significant role in the wear process and contributes to the overall tribological behavior of the Cu–Be alloys [32]. By recognizing the interrelationship between hardness, wear resistance, and thermal conductivity, the authors emphasize the importance of selecting electrode materials with suitable alloying elements desirable for achieving optimal performance in spot welding applications.

Hardly any comparative studies have been conducted to analyze the wear behavior of Cu–Cd, Cu–Be, and Cu–Cr–Zr alloys when employed as spot-welding electrode materials. This article aims to provide a comprehensive comparison of the wear performance exhibited by these three Cu alloys under diverse load, temperature, and time conditions using pin-on-disc set-up. Additionally, SEM analysis has been employed to investigate the wear mechanism of these materials, enabling a deeper understanding of their behavior in relation to wear.

2. Materials

Electrodes for resistance welding should be made from materials with high enough thermal and electrical conductivities, along with sufficient strength to withstand deformation at the pressures and temperatures encountered during operation. When selecting electrode materials, it is necessary to consider the materials’ degrees of hardness and the temperatures at which they anneal. Resistance spot welding with a wide range of parameter settings for time, current, and electrode force can produce a satisfactory weld on low- to medium-carbon steel. The presence of carbon in steel has a significant and negative impact on both its weldability and its joint strength. Cracks or tears at the weld interface or nugget may be caused by excessive carbon, sulphur, or phosphorous in the material.

Electrode materials were prepared by melting plates of commercial-grade electrolytic copper (99.9% purity) and powder of zirconium/chromium/Cd/Be (as required), and by casting the molten mixture into a circular mould to obtain a cylindrical shape at temperatures ranging from 1100 to 1300 degrees Celsius. Post-curing was carried out for six hours. The surface scale was removed to complete the cleaning and finishing processes. After heating the rods to 750–800 degrees Celsius, the bars with a diameter of 15 mm were extruded from them. Before beginning the machining process, the bar was cleaned with acid and turned to achieve the desired final dimensions of 10 mm in diameter and 30 mm in length.

Table 1. Chemical compositions of Cu alloys.

	Basic Elements (Mass. %)
Material	Cu	Cr	Cd	Be	Zr
Cu–Cd	99.60	--	~0.40	--	--
Cu–Be	99.80	--	--	~0.20	--
Cu–Cr–Zr	97.85	~2.00	--	--	~0.15

details the chemical makeup of the three different alloys.

To observe the microstructure of Cu–Cr–Zr, a sample was prepared by a process of cutting, grinding, and polishing according to the standard metallographic procedure. The sample was cleaned using acetone to remove any remaining debris or polishing compounds. An etchant was prepared with 100 mL of water. We added 10 g of FeCl₃ (Ferric Chloride) to it and stirred it continuously until FeCl₃ dissolved completely. Once the FeCl₃ had dissolved, 50 mL of hydrochloric acid (HCl) were added to the solution. Next, 10 mL of nitric acid (HNO₃) were added. We applied several drops of the prepared etchant solution to the surface of the sample. The etchant will selectively attack different phases or constituents of the Cu–Cr–Zr alloy, revealing their microstructural features. Microstructure Cu–Cr–Zr was observed under a microscope (NIKON EPIPHOT 200), as shown in Figure 1. Cu–Cr–Zr alloys typically consist of multiple phases, including a copper-rich matrix phase and various precipitate. Depending on the alloy composition and heat treatment, various precipitates are formed within the copper matrix. Chromium (Cr) precipitates segregate within the copper matrix and form small precipitates. These precipitates can influence mechanical and corrosion properties of the alloy. Zirconium can also form precipitates within the copper matrix. These precipitates contribute to strengthening the alloy and improving its high-temperature properties. Fine-grained structures are typically observed in Cu–Cr–Zr alloys.

After measuring the samples’ electrical resistivity with a BSZ-010-2 micro-ohmmeter, the results were converted into electrical conductivity using the International Annealed Copper Standard (IACS%). Before carrying out wear experiments, the electromechanical properties of an alloy were investigated. Archimedes’ principle was utilized at room temperature to perform the density measurement. Experiments with a universal tensile testing machine were carried out to understand Cu alloys’ yielding behaviour when subjected to applied tensile stress. (FIE makes UTES-100). Through the use of an extensometer, the loads, as well as the displacements, were continuously monitored, and the yield strengths of all three materials were recorded. The results can be found in

Table 2. Mechanical, Electrical and Thermal properties of sample materials.

Material	Electrical Conductivity (% IACS)	Thermal Conductivity (W·m−1K−1)	Rockwell Hardness (B Scale)	Yield Strength (MPa)	Density (gm/cm3)	Percentage Elongation (%)
Cu–Cd	90.1 ± 0.5	200 ± 10	70 ± 1.0	475 ± 5	8.89 ± 0.0	17.9 ± 1%
Cu–Be	50.8 ± 0.5	140 ± 10	95 ± 1.0	495 ± 5	8.89 ± 0.0	12.7 ± 1%
Cu–Cr–Zr	86.3 ± 0.5	190 ± 10	85 ± 1.0	425 ± 5	8.89 ± 0.0	18.6 ± 1%

. It was discovered that the elongation percentages for Cu–Cd, Cu–Be, and Cu–Cr–Zr were, respectively, 17.9%, 12.7%, and 18.60%. The sudden fracture in Cu–Cd and Cu–Be alloys demonstrates their brittle nature. The ASTM E 18 standard dictates how the Rockwell hardness test should be carried out. The symbol HR denotes the Rockwell hardness in addition to the scale designation (HRB indicates the Rockwell hardness according to the B scale). For measuring the hardness of copper alloys, the Rockwell B scale with a steel indenter of 1.58 mm diameter and a significant load of 100 kgf is recommended. However, in addition to the test material, the thickness of the specimen and its location are also factors that are considered when choosing a scale. In Table 2, the mechanical, electrical, and thermal properties of all three sample materials are compared and contrasted with one another.

Sample Preparation

As stated above, pins were prepared of various Cu alloys and they were machined to have 10 mm diameters and 30 mm lengths. A small hole was drilled into one side of the pin to pinpoint the temperature sensor. These pins were held in a clamping fixture during the test.

An N1-grade surface finish was maintained. An N1-grade surface finish indicates 0.025 µm, and this surface was obtained via a delicate grinding operation. Surface roughness strongly influences tribological performance in sliding contacts. In order to maintain even contact geometry, the surface finish was maintained at the bottom of the pin, where metal-to-metal contact is desired. We measured it via a Surftest SJ-210 Mitutoyo surface roughness tester.

3. Experimentation and Procedure

3.1. Experimental Set-Up

In spot welding, temperature and load are applied to obtain coalescence. The load is supplied externally to hold the workpieces in contact and thereby control the electrical resistance at the interface. Temperature, load and holding time can be simulated in a pin-on-disc apparatus, and hence are considered independent variables for experimentation. In this study, however, discs were rotated at constant sliding speeds throughout the experimentation to understand wear behaviour at accelerated test conditions. The wear experiments were carried out on DUCOM pin-on-disc wear tester. The pin-on-disc machine (as shown in Figure 2) consisted of a vertical axis rotating disk made up of EN-31 (AISI 52100) material and calibrated dead-weight-loaded pin, which was held in jaws. The tests were conducted as per ASTM G-99 standards [33].

The pin-on-disk set-up was instrumented with a load cell of least 0.1 N and a linear variable differential transformer (LVDT) to measure linear displacement in µm. The cylindrical pin specimen with a flat surface at one end and a hole for the temperature sensor at the other were pressed against a rotating disk for experimentation. The disc was rotated constantly throughout the experimentation with a track radius of 100 mm for 15 min, 30 min and 45 min. Temperature was set for 50 °C, 100 °C and 150 °C for different runs at 50 N, 100 N and 150 N. The data acquisition system and WINDUCOM 2010 software recorded the results.

3.2. Wear Test Procedure

A single electrode tip is recommended for approximately 600 to 1200 weld spots without severe plastic deformation and material loss in spot welding. In this study, three electrodes were considered for experimentation. Experiments were performed as the per ASTM G99-04 standard using a cylindrical shape pin specimen of a 8 mm diameter to determine the wear of materials during sliding using a pin-on-disc apparatus. A separate pin was used for each experiment, with an EN-31 counter-face disk of higher hardness than that of a pin. The pin was appropriately fastened in the holding jaws, and a flat face was placed on the disc. However, the surface with a hole was used to place the temperature sensor. The wear track diameter was fixed at 100 mm. The disc’s rotational speed was kept constant and set at 380 rpm.

Table 3. Assignment of levels to the factors.

Factors	Levels			Units
	I	II	III
Material	Cu–Cd	Cu–Be	Cu–Cr–Zr	--
Temperature	50	100	150	°C
Time	15	30	45	Min
Load	50	100	150	N

depicts the factors under consideration and their corresponding levels. Experiments were performed and analyzed using Taguchi L9 orthogonal array. The first column was assigned to material, the second to temperature, the third to time (V), and the fourth to load; however, the sliding speed was kept constant for all experimental runs. The output response, i.e., wear (µm), was recorded from the data acquisition system. Each run was repeated twice in order to observe the repeatability of the readings.

4. Results and Discussion

The influence of electrode material, temperature, time and load on wear experiments was examined. Signal noise (S/N) ratios are preferred over average (or) mean to analyze experimental results with multiple runs. In Taguchi analysis, quality characteristics are represented by S/N ratios. Complete factorial design of experiments involves more cost and time. However, the Taguchi method is more accurate and versatile than the fractional factorial design of experiments.

Since wear should always be minimum, minor is better and is considered an objective function. S/N ratios and mean-square deviation (MSD) were evaluated using Equations (1) and (2). Further analysis was conducted using MINITAB20 statistical software. The per cent contribution of each parameter were evaluated.

$$\frac{S}{N}=-10 \left(MSD\right)$$

(1)

where MSD = mean-square deviation.

For smaller is better:

$$MSD=\left(K_1{}^2+K_2{}^2+K_3{}^2+\cdots \cdots \cdots \cdots \cdots \cdots K_n{}^2\right)/n$$

(2)

Pure sum of squares (s′) have been calculated as follows,

$$s^{\prime }=Sum of squares-\left(error\times d.f\right)$$

(3)

Experimental results and response table for SN ratios are shown in

Table 4. L₉ Orthogonal Array for Pin-On-Disc Experiment.

Run	Material	Temperature °C	Time (Min)	Load (N)	Wear1 (µm)	Wear2 (µm)	Mean Wear (µm)	SN Ratios
1	Cu–Cd	50	15	50	434	425	429.5	−52.6716
2	Cu–Cd	100	30	100	584	573	578.5	−55.2550
3	Cu–Cd	150	45	150	657	683	670.0	−56.5313
4	Cu–Be	50	45	100	444	443	443.5	−52.9431
5	Cu–Be	100	15	150	474	475	474.5	−53.5286
6	Cu–Be	150	30	50	407	403	405.0	−52.1641
7	Cu–Cr–Zr	50	30	150	294	275	284.5	−49.1006
8	Cu–Cr–Zr	100	45	50	322	311	316.5	−50.0329
9	Cu–Cr–Zr	150	15	100	251	257	254.0	−48.1007

and

Table 5. Response Table for Signal-to-Noise Ratios.

Level	Material	Temperature	Time	Load
1	−54.82	−51.57	−51.62	−51.43
2	−52.88	−52.94	−52.10	−52.17
3	−49.08	−52.27	−53.05	−53.17
Delta	5.74	1.37	1.43	1.74
Rank	1	4	3	2

respectively. Figure 3 and Figure 4 show the main effect of data means and the main effect of the S/N ratios on wear, respectively. From the main effect plot for data means, it is observed that the wear rate is minimum for Cu–Cr–Zr at 500 °C, 15 min and 50 N of load, depicting optimum conditions for minimal wear. It is observed that the wear rate increases with an increase in temperature, load and time; at high temperatures and loads, severe plastic deformation of softer material (copper) causes ploughing. From

Table 6. Analysis of Variance.

Source	DF	Adj SS	Adj MS	% Contribution
Material	2	113,683	56,841	77.04
Temperature	2	8468	4234	5.73
Time	2	12,848	6424	8.70
Load	2	12,556	6278	8.50
Error	0
Total	8	147,555

, the electrode material is essential and contributes around 77%. Holding time and applied load contribute around 8 to 9%, while electrode tip temperature contributes up to 5.73%. Generally, average wear increases with more sliding time as Cu becomes more ductile with friction and temperature rise. In situ linear wear was measured using an LVDT sensor. During experiments on Cu–Cd and Cu–Be, some mindful sounds and chatter were observed when a hard spot came into contact with the pin during severe sliding conditions. Due to this, three body wear was also observed.

Specific wear rates have been calculated for different loading conditions using Equation (4). By considering the wear rates and relating them with the morphological observations (Figure 5), we present further insights into the wear behavior, an understanding the underlying causes, and a discussion of wear the mitigation of materials in more detail.

Specific Wear Rate = (Linear Wear/Applied Load) × (10⁻⁶/Sliding Distance)

(4)

Figure 6 shows the morphologies of different Cu alloys sliding under various loads, temperatures and time conditions. A large amount of galling with deep furrows was observed on the worn surfaces at higher temperatures and loads (Figure 6c,e,h,i). This indicates types of wear related to metal transfer and adhesion due to high shear and low everyday stresses. Abrasive wear with light furrows was observed on the worn surface at 50 N load due to hard asperities being present on the EN31 disc surface and repeated sliding (Figure 6f). The extent of wear increases with time and temperature due to the formation of hard oxide debris between the interfaces, and scratches are observed in front of hard spots (Figure 6d,g). Hence, both adhesive and abrasive wear mechanism are observed. The amount of wear is correlated to the rise in temperature and contact pressure on sliding interfaces; similar results were reported by researchers [7,8,20]. An increase in temperature may cause localized welding, which leads to severe plastic deformation/ploughing under sliding conditions. Thermal degradation of the ingredients is also involved in controlling the amount of wear in the case of friction materials. Black oxide, like layers, forms in case Cu–Cr–Zr helps to minimize wear. Cd is a more complex element, and hardness and wear increase with hardness; hence, more wear is observed in the case of Cu–Cd [18]. A comparison of wear of Cu–Cd, Cu–Be and Cu–Cr–Zr alloy under different temperatures, time and load conditions was conducted. It was observed that, comparatively, Cu–Cr–Zr alloy showed better wear resistance. Additionally, Cu–Be created an inhalation hazard known as chronic beryllium disease. This may occur due to exposure to dust or fumes from beryllium metal, metal oxides, alloys, ceramics or salts. Hence, Cu–Cr–Zr can be the best alternative material for the resistance/spot welding electrode. Further studies on processing methods of Cu–Cr–Zr by cold working and ageing and its effect on the life expectancy of this material are needed. Detailed investigations of in situ spot/resistance welding, considering welding current, welding time and holding pressure, is recommended when welding low-to-medium-carbon steel materials on the basis of welding strength and quality.

Furthermore, the specific composition of the Cu–Cr–Zr alloy plays a significant role in its wear resistance. The addition of chromium (Cr) and zirconium (Zr) to the copper (Cu) matrix can alter the alloy’s microstructure and enhance its wear resistance properties. These alloying elements are forms of intermetallic compounds or secondary phases that provide increased hardness and improved wear resistance. By introducing alloying elements into the copper matrix, solid solution strengthening occurs, leading to improved mechanical properties such as hardness and wear resistance. The microstructure of the Cu–Cr–Zr alloy depicts fine grain size, phase distribution, and the presence of precipitates as compared to Cu–Be and Cu–Cd alloys, and hence influences its wear resistance. Fine-grained microstructures or the presence of hard precipitates can hinder the movement of dislocations and reduce wear. The Cu–Cr–Zr alloy may possess a microstructure that promotes higher wear resistance compared to other alloys.

In this study, a detailed analysis of material surfaces is performed based on various factors, such as alloying elements, surface roughness, the presence of wear-related phenomena like wear tracks, debris, or formation of tribofilms. The characteristics of these tribofilms can vary between Cu–Cd, Cu–Be and Cu–Cr–Zr materials, leading to differences in wear performance. These factors can provide insights into the reasons behind different wear performance.

5. Conclusions

The following conclusions can be made from this work on the effect of the sliding wear behaviour of three different Cu alloys rubbing against EN 31 disc under different sliding conditions.

• For all three types of copper alloys, the amount of wear that occurs is proportional to the load, the sliding time, and the temperature. In sliding wear conditions, the resistance of the Cu–Cr–Zr alloy is superior to that of the Cu–Cd and Cu–Be alloys.
• Wear patterns caused by sliding conditions predominately appear for the adhesive and abrasive types in the SEM micrographs. Under high-load and -temperature conditions, a mechanism that causes galling, ploughing, and scratching was observed. These wear mechanisms lead to surface damage, material transfer, and eventual degradation of the material’s mechanical properties.
• It has been found that the formation of tribal layers at high temperatures has a significant impact on the amount of wear experienced by copper-induced metallized carbon.
• According to Taguchi analysis and scanning electron micrographs, the degree to which a material’s chemical composition affects wear behaviour in resistance spot welding electrodes is a significant factor. By adding Cr and Zr, the wear rate can be significantly reduced. Cu–Cr–Zr alloys typically consist of multiple phases, including a copper-rich matrix phase and various precipitates. These precipitates contribute to strengthening the alloy and improve its high-temperature wear-resistant properties.
• According to the ranking of the parameters, the material is the factor with the greatest influence (77%). The effect of temperature is approximately 9%, followed by time and load. Additionally, specific wear rates of the materials under consideration have been compared at different loading conditions and it is observed that Cu–Cr–Zr has the lowest wear rate compared to the other two materials. The developed ternary alloy has synergistic effects on wear resistance, providing superior performance compared to binary alloys.