Investigation of deformation and fracture of composition with sprayed coatings under threepoint bending

Flame spraying and activated arc-metallization are prevailing and inexpensive techniques for machine parts protection and recovery. Selection of optimal coatings thickness and estimation of their adhesive strength is the actual problem during design of "sprayed coating-substrate" compositions. For attestation of sprayed coatings and optimization of coating deposition modes it is necessary to investigate behavior of the compositions under mechanical loading. Three-point bending is a very informative and operative test that provides express estimation of strength properties of the composition. Application of television-optical measuring technique makes rapid analysis of the strength properties of coatings possible, in order to optimize coating spraying modes. Registration of loading diagram allows estimating the level of external stress and strain, which correspond to the coating cracking. Recommendations on improvement of composition service properties are given.