Fabrication of TiN coatings using mechanical milling techniques

Mechanical milling and ultrasonic mechanical coating and armouring (UMCA) were used for depositing of TiN coatings on different substrates. A powder and balls were placed in a vibration chamber. The substrate can be placed in the chamber with the powder or it can be fixed to the top of the chamber. During a mechano-activation process, the substrate surface is subjected to high-energy ball impacts. Powder particles trapped between the ball and surface cold weld to the surface. TiN coatings can be formed in a short time at room temperature under ambient atmosphere. The thickness, roughness and structure were found to depend on substrate hardness, milling intensity and size of initial TiN particles. Coatings having thicknesses up to 18 μm were fabricated through mechanical milling when the 7 mm balls and 50 nm particles were used. UMCA could be used to form smooth uniform coatings (thickness: ∼5 μm) after treatment for 6 min on 10 cm plates.