engleski

The Quality Influence of Base Material Surface Preparation on the Durability of a Sprayed Layer Against Radial and Axial Shear

For the purpose of this experiment, respective surface of 42CrMo4 base material specimens were prepared for spraying using different technologies: turning, cutting of radial notches and cutting of axial notches. Gas aided thermal spraying of wire material was performed, laying a first layer of a nickel aluminum compound and a final Chrome Molybdenum Steel coating. Metallographic structure analysis and hardness measurement suggested that surface preparation quality does not affect hardness of the sprayed layer, but it thickness. Using a suitable tool, specimens were examined on radial and axial shear and these results were compared to previus ones. It could be determined that the notch size significantly affects both the thickness of the intermediate layer and its even distribution around the edge of the notch. A smaller radial notch allows for a higher torque momentum at radial shear, whilst best overall properties are achived with axial notches subjected to radial loads. Testting axial shear, the cutting power proved dependant of the depth of radial notches, where low depth was inherent with low shear resistance.

base material; metal spraying; radial and axial shear; surface preparation

nije evidentirano