Copper-Nickel/SiC composites for applications on contact electrodes.

Area of Science:

• Materials Science
• Metallurgy
• Composite Materials

Background:

• Copper (Cu) and its alloys are common in low-voltage circuit breakers but form high-resistance oxides in oxygenated environments.
• Nickel (Ni) addition enhances Cu alloys' resistance to corrosion, humidity, and improves mechanical properties.
• Silicon carbide (SiC) offers mechanical strength, moldability, and low cost for composite reinforcement.

Purpose of the Study:

• To develop and characterize novel copper-nickel matrix composites reinforced with SiC microparticles.
• To evaluate the influence of SiC loading and particle size distribution on composite properties.
• To assess the suitability of these composites for metal contact applications.

Main Methods:

• Powder metallurgy was employed to manufacture Cu-Ni/SiC composites.
• Experimental characterization included hardness, wear resistance, and electrical conductivity measurements.
• Three SiC particle size distributions were investigated with varying ceramic loadings.

Main Results:

• Composites with 10 wt% and 20 wt% SiC showed promising properties for electrode applications.
• Achieved hardness ranged from 55-65 HR30T, ensuring strength with minimized welding.
• Specific wear resistance of ~10^-5 mm³N^-1m^-1 and electrical conductivity of ~20 %IACS were obtained.
• Homogeneous particle distribution was observed in the solid material.

Conclusions:

• Cu-Ni/SiC composites exhibit comparable performance to commercial Ag/WC materials.
• These composites present a viable alternative for metal contact applications, balancing strength, wear resistance, and conductivity.
• The properties are tunable based on SiC concentration and particle size.