Effect of dry milling and MWCNTs content during fabrication of Fe-MWCNTs metal matrix composite by high energy planetary milling followed by conventional sintering

Abstract

The present paper discusses about fabrication of iron-based composite using multi walled carbon nanotubes (MWCNTs) as reinforcing agent by using high energy planetary milling followed by conventional sintering. Composites containing iron and 0.5, 1.0, 2.0 and 4.0 vol. % MWCNTs powder mixtures are milled in dry (argon atmosphere) condition for 10 h in a dual drive planetary mill (DDPM). It has been observed that after 10 h of milling, average particle size decreases from 36 to 10 µm. The field emission-scanning electron microscopy (FESEM) images show that final powder is spherical in shape after milling. Raman spectroscopy reveals distortion and formation of defects in MWCNTs after 10 h of milling and MWCNTs are stable upto 900 °C and losses stability when consolidated at both 1200 and 1300 °C. The maximum value of relative density and hardness are 88 % and 252 VHN respectively for the Fe-0.5 vol. % MWCNT composite sintered at 1300 °C for 2 h. The maximum value of yield strength and compressive strength are also achieved for Fe-0.5 vol. % MWCNTs composite sintered at 1300 °C and the values are 350 MPa and 580 MPa respectively.