Effect of annealing treatment on the structure and properties of the nanograinedTiN coatings produced by ultrasonic-based coating process

摘要

An ultrasonic mechanical coating and armouring (UMCA) process was used for the deposition of thenanograined TiN coatings. During the UMCA process, the substrate surface was subjected to high-energyball impacts. The repeated substrate-to-ball collisions made the precoated TiN particles cold weld toeach other and to the substrate. The UMCA method allows nanograined TiN coatings to be produced ondifferent substrates in a short time at room temperature in an ambient atmosphere. Under the appliedcompressive loading, the substrate became strongly deformed. The grain refinement occurred and manyrandomly orientated nanosized grains developed near the substrate surface. Annealing treatment in tem-peratures ranging between 200 °C and 600 °C improved adhesion of the coatings and increased hardness.The nanoparticles had a tendency to consolidate with increasing annealing temperature. The growth ofcrystallites started at 400 °C. After annealing at 600 °C, a solid state reaction between Al and TiN leads tothe formation of a new phase that could be intermetallic compound A1Ti3.