Fe-C-Cr-Nb alloy steel surfacing layers with different contents of C and Cr were prepared on 45 steel base metal by selfshielded flux-cored wires with distinct amounts of high carbon chromium iron addition and melt arc surfacing. The composition and microstructure changes of the surfacing layer were tested and analyzed. The surfacing test plate was processed into a pulling specimen, and the bonding strength between the surfacing layer and the 45 steel base metal was tested with a self-designed pulling test method. The fracture location of the pulling specimen and fracture characteristics were observed by a metallurgical microscope and a scanning electron microscope. The result shows that with the increase of the amount of high carbon chromium iron added to flux-cored welding wire, the content of C and Cr in the surfacing layer increases, and the NbC hard phase disperses. The microstructure of the steel matrix changes from mixed martensite + residual austenite to high carbon martensite + residual austenite, and then independent austenite appears. The hardness of the surfacing layer first increases and then decreases. The bonding strength between the surfacing alloy and the 45 steel base metal first decreases and then increases, and the fracture location is at the bottom of the surfacing layer or the fusion zone with mostly quasi-cleavage characteristics. When the additional amount of high carbon chromium iron reaches 13%, thee pulling specimen exhibits significant deformation with the highest bonding strength, and the fracture is close to the fusion line, where there are numerous tearing edges and shallow dimples.

Pulsed laser deposition technique was applied for covering elastic cast-polyurethane membranes with titanium nitride and boron nitride layers. The deposition process was realized using a Nd:YAG laser with Qswitch in stages; firstly the membranes were coated with ultra-thin titanium nitride layer (TixN) by evaporation of a metallic titanium disk in nitrogen gas atmosphere and then a layer of boron nitride (BN) was deposited by ablation of hexagonal h-BN target in argon atmosphere. The surface morphology was observed by scanning electron microscopy. Chemical composition was analyzed by energy dispersive X-ray spectrometry. The phase analysis was performed by means of grazing incidence X-ray diffraction and attenuated total reflection infrared spectroscopy. The crystallographic texture was measured. The wear test was performed by pin-on-disk method. Hexagonal boron nitride layers with (0001)[uvtw] texture with flake-like grains were fabricated. The structure and texture of boron nitride was identical irrespectively of substrate roughness or BN thickness. Pin-on-disk wear tests showed that the coatings effectively decreased the friction coefficient from two to even four times comparing to pure polyurethane and polyurethane covered with graphite. This proved that deposited layers can replace graphite as a lubricating material used to protect polymer surfaces.