This paper presents new results of studying the influence of parameters of microplasma spraying (MPS) of Zr wire on the structure of Zr coatings. The coating experiments were accomplished in a two level fractional factorial design. Individual particles of sprayed Zr wire and their splats on the substrate were collected under various spraying parameters (amperage, spraying distance, plasma gas flow rate and wire flow rate) and evaluated by Scanning Electron Microscopy (SEM) to establish the effect of particle size and shape on the coating microstructure. The particles were characterized by measurement of their sizes and the obtained results were evaluated in terms of their degree of melting. This was compared with the experimentally observed coating microstructure type and finally correlated to the investigated coating porosity to select the specific MPS parameters of Zr coatings depositing onto medical implants from Ti alloy. It was found that the main parameters influencing the size of the sprayed Zr particles and the porosity of the Zr coatings are the plasma gas flow rate and amperage. It was demonstrated that it is possible to control the porosity of Zr microplasma coatings in the range from 2.8% to 20.3% by changing the parameters of the MPS. The parameters of microplasma spraying of Zr wire were established to obtain medical implant coatings with porosity up to 20.3% and pore size up to 300 μm.

No abstract

The paper presents new results of automated path planning for an industrial robot manipulator performing microplasma spraying of coatings on substrates with complex surface shapes. Path planning and automatic generation of the manipulator motion program are performed using data of a preliminary 3D surface scanning by a laser triangulation distance sensor installed on the same robot arm. The automatic manipulator working tool path planning algorithm is based on the choice of the starting segment of the working tool trace as a geodetic line on the surface. An algorithm for optimal spatial curve approximation by a sequence of line segments and arcs has been developed as a part of the automatic manipulator program generation system. The developed algorithms and their software implementation were experimentally tested through robotic microplasma spraying of a protective coating on the surface of a jaw crusher plate, which was then successfully operated for crushing mineral raw materials.

No abstract

No abstract