Preparation of γ-Al_2O_3 coating on 304 stainless steel by sol electrophoretic deposition

γ-Al2O3 coatings were prepared on 304 stainless steel by sol electrophoretic deposition,and characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The adhesion of coating was examined by ultrasonic vibration. The factors affecting the coating performance were studied,including the volume fraction of γ-AlOOH sol and the mass concentration of nano-sized alumina in electro-phoretic deposition solution,deposition voltage and time,and stirring rate. The results indicated that a stable electrophoretic deposition solution can be obtained by the addition of γ-AlOOH sol to absolute ethanol,and the deposition weight and stability of coating improved by the addition of nano-Al2O3. The γ-Al2O3 coating obtained with γ-AlOOH sol 30%-40% (volume fraction) and nano-alumina 20-30 g/L at deposition voltage of 10 V and stirring rate of 375 r/min for 5-10 min is well adhered after calcination at 600 °C for 3 h.