Experience in Detonation Nano-Structures Coating Application Technologies using Condensed Explosives and Gas Mixtures

Objectives: The article gives an insight to reviews and research in detonation nano-structured coating, using condensed explosives and gas mixtures applied at the SamSTU and other facilities in the Samara region. Methods: The detonation method allows obtaining nanostructured composite materials and coatings that are unique in their physical and mechanical properties. Detonation sputtering is a coating technology that relies on gas explosion energy for heating and accelerating a powdered material. Findings: The experience of industrial use of wear-resistant detonation coatings and possible applications has been demonstrated. According to our research, it is possible to raise surface hardness of specimens by more than 3 times and 2 to 10 times with wear resistance. It is shown that the suggested technology ensures higher stability of mechanical properties of coatings. Thus, original hardness of steel specimens was in the range of 400 to 600 kgf/mm². Hardness values of detonation-sputtered hard-alloy coatings were ca. 1,200 to 1,400 kgf/mm² and activation energy was up to 350 kJ/mole, which is typical of hard-alloy materials. Scratch-hardness tests showed rather high coating and base material adhesion values. According to the preliminary data, shear strengths over 150 MPa may be achieved. Thus, aluminum-substrate Al₂O₃ strength was 163 MPa and aluminum-substrate and Ti-subcoat Al₂O₃ strength was 152 MPa. Novelty/improvements: The suggested novel method enables to increase projection velocity of powdered materials and creates an extra heat effect giving plastic properties to the injected materials.