The addition of superelastic NiTi to electroless Ni-P coating has been found to toughen the otherwise brittle coatings in static loading conditions, though its effect on erosion behaviour has not yet been explored. In...The addition of superelastic NiTi to electroless Ni-P coating has been found to toughen the otherwise brittle coatings in static loading conditions, though its effect on erosion behaviour has not yet been explored. In the present study, spherical WC-Co erodent particles were used in single particle impact testing of Ni-P-nano-NiTi composite coatings on API X100 steel substrates at two average velocities—35 m/s and 52 m/s. Erosion tests were performed at impact angles of 30°, 45°, 60°, and 90°. The effect of NiTi concentration in the coating was also examined. Through examination of the impact craters and material response at various impact conditions, it was found that the presence of superelastic NiTi in the brittle Ni-P matrix hindered the propagation of cracks and provided a barrier to crack growth. The following toughening mechanisms were identified: crack bridging and deflection, micro-cracking, and transformation toughening.展开更多
Powder metallurgy (PM) is a very interesting metal manufacturing technique in the production of automotive components of a net or near net shape. In this research, the electrochemical corrosion behavior of a commercia...Powder metallurgy (PM) is a very interesting metal manufacturing technique in the production of automotive components of a net or near net shape. In this research, the electrochemical corrosion behavior of a commercially available aluminum powder alloy known as Alumix 321 was investigated and compared to wrought alloy AA6061 in 3.5 wt% NaCl solution using Electrochemical Impedance Spectroscopy Measurements (EIS). Alumix 321 alloy samples were prepared by pressing the powder at pressures ranging from 50 to 500 MPa and subsequently sintering them for 30 min at 630<span style="white-space:nowrap;">°</span>C. It was found that the presence of pores and their morphology strongly affect the corrosion behavior the PM samples.展开更多
文摘The addition of superelastic NiTi to electroless Ni-P coating has been found to toughen the otherwise brittle coatings in static loading conditions, though its effect on erosion behaviour has not yet been explored. In the present study, spherical WC-Co erodent particles were used in single particle impact testing of Ni-P-nano-NiTi composite coatings on API X100 steel substrates at two average velocities—35 m/s and 52 m/s. Erosion tests were performed at impact angles of 30°, 45°, 60°, and 90°. The effect of NiTi concentration in the coating was also examined. Through examination of the impact craters and material response at various impact conditions, it was found that the presence of superelastic NiTi in the brittle Ni-P matrix hindered the propagation of cracks and provided a barrier to crack growth. The following toughening mechanisms were identified: crack bridging and deflection, micro-cracking, and transformation toughening.
文摘Powder metallurgy (PM) is a very interesting metal manufacturing technique in the production of automotive components of a net or near net shape. In this research, the electrochemical corrosion behavior of a commercially available aluminum powder alloy known as Alumix 321 was investigated and compared to wrought alloy AA6061 in 3.5 wt% NaCl solution using Electrochemical Impedance Spectroscopy Measurements (EIS). Alumix 321 alloy samples were prepared by pressing the powder at pressures ranging from 50 to 500 MPa and subsequently sintering them for 30 min at 630<span style="white-space:nowrap;">°</span>C. It was found that the presence of pores and their morphology strongly affect the corrosion behavior the PM samples.
