Investigation of the joinability cold pressed and sintered metal matrix silicon carbide reinforced composites by diffusion welding

Copper is widely used in industrial applications because of its high electrical and thermal conductivity, easiness of processing and good corrosion resistance. However, copper also has some distinct limitations such as low hardness, low tensile yield strength, and poor creep resistance. Copper is one of the first and processed metals of human history and is the second metal with the best thermal and electrical conductivity after silver. The use of carbides in metal or ceramic matrix is becoming increasingly popular in the production of abrasion-resistant materials, and the industry has an important share of usage. A copper-based composite matrix is reinforced with ceramics like SiC particles. Silicon carbide (SiC) also has low density, high strength, high hardness and high Young's modulus, which are considered to be reinforcement for metal matrix composites (MMCs). The current study is an effort to study the diffusion welding of a copper-based composite matrix reinforced with silicon carbide (SiC). The reinforcement is added in the form of silicon carbide in the various ratios 5%, 10%, and 15% SiC by volume of copper alloy that is produced by using uniaxial cold pressing under a pressure of (350MPa) of pressure and then sintered at 800 °C for 45 minutes. The Copper-based material are joined by diffusion welding in argon atmosphere under 2 MPa pressure, using temperatures 800 °C and 850 °C and diffusion times 30, 45 and 60 minutes to make the materials more applicable in the industry. Determining the effect of parameters on hardnes and density are examined and microstructure observed by scanning electron microscopes (SEM). Finally, three-point bending test applied and the results compared to unwelded samples. The best results were obtained in terms of transverse rupture strength at 850oC and 60 minutes diffusion welding conditions with 10% SiC additive. These obtained values correspond to 90% of the sample without welding.