Physical properties and microstructural performance of Sn modified laser amorphous-nanocrystals reinforced coating

An amorphous-nanocrystals reinforced composite coating was fabricated on TA15 titanium alloy substrate by laser alloying of Al–Sn–B4C–SiC–TiN–Y2O3 mixed powders, which greatly improved the wear resistance of substrate. Experimental results indicated that Al–Sn nanocrystalline phases were produced through in situ metallurgical reactions, which blocked the motion of dislocation. The productions of the eutectics, such as Ti–Si greatly promoted the formation of amorphous phases in such coating. Compared with the substrate, higher wear resistance of laser alloying coating was mainly ascribed to the hard phase, amorphous-nanocrystalline phases and fine grain strengthening. This research provided essential theoretical and experimental basis to promote the application of laser alloying technique in modern aviation industry.

The Al-Sn nanocrystalline phases were produced through in situ metallurgical reactions, which blocked the motion of dislocation.Figure optionsDownload as PowerPoint slideHighlights
► The elements with short atomic radius increased irregular stacking of alloy liquid phase structure.
► When temperature exceeded a certain value, a portion of Sn and Al melted due to the eutectic reaction.
► Production of eutectics, such as Si-Ti in coating greatly promoted formation of amorphous phases.
► Al-Sn nanocrystalline phases were produced through in situ metallurgical reactions.