Structure and Wear Resistance of Composite TiC-NiMo Coating Produced by L-DED on Ti-6Al-4V Substrate

Abstract

Fabrication of W- and Co-free wear-resistant cermets is a vital task in modern machinery due to the toxicity of Co-based products and poor availability of Co and W containing raw materials. In this paper, a TiC-NiMo coating produced by laser-directed energy deposition (L-DED) on a Ti-6Al-4V substrate was demonstrated. Mechanical alloying of TiC, Ni and Mo powders followed by spray-drying was proposed to fabricate a feedstock spherical composite powder suitable for an L-DED machine. It was shown that this method is more applicable in the case of a TiC-containing composition than gas atomization and plasma spheroidization methods. The size of the resulting particles was in the range of 10–100 μm while the size of the 70 vol.% was in the range of 45–75 μm. L-DED provided a good adhesion of the coating, though the presence of pores and transverse cracks was also observed. The coating’s hardness was up to 1500 HV, which is not inferior to the hardness of known TiC-based cermets and is promising for obtaining a good wear resistance of the coating. It was shown that it depended on the thickness due to the mixing zone influence. The coating structure contained TiC- and Mo-based precipitates and a Ni-based binder. The weight loss of the coating samples after an abrasive wear test with 4000 revolutions of a testing wheel was 0.0464 g and that can be considered insignificant. The wear did not lead to the appearance of new defects and cleavage of the coating. Further optimization of the component ratio and L-DED parameters could help to improve the performance of the coating and make this technology rather promising to improve the wear resistance of machinery parts working in high-wear environments.

Microstructure and Wear Resistance of Si-TC4 Composite Coatings by High-Speed Wire-Powder Laser Cladding

“…The TC4 wire cladding coating exhibits a plastic deformation area in the presence of a large abrasion area, whereas the composite coating eliminates the abrasion area. This change in the wear mechanism is associated with the microhardness of the coating [ 44 , 45 ]. The TC4 coating exhibits low microhardness and is susceptible to adhesive wear, whereas the composite coating demonstrates relatively high microhardness and is resistant to adhesive wear.…”

“…This leads to a stronger coating produced by the second phase of the strengthening effect, resulting in a gradual increase in the microhardness of the coating. Higher hardness is very favorable for improving the hardness of composite coatings [43,44]. Figure 9 shows the plots of the average friction coefficient and wear weight loss at various feed rates.…”

Experimental Investigations in the Processing of AISI H11 Powder Blends Enriched with Tungsten Carbide Nanoparticles for the Additive Manufacturing of Tailored Hot Working Tools in the Directed Energy Deposition (DED-LB/M)—Impact of Tungsten Carbide Nanoparticles on Microstructural and Mechanical Characteristics

“…Examples include the repair of worn injection molds or forming tools [1][2][3], or the tip repair of turbine blades [4][5][6]. Besides that, DED-LB/M is industrially used as coating technology for the deposition of wear-and corrosion-resistant coatings on highly stressed functional parts in order to improve their mechanical properties and practical performance (e.g., increased life-time) [5,7,8]. Due to the ongoing improvement in and progression of system technology applied for DED-LB/M and the availability of CAD/CAM software for tool path planning, this laser-based manufacturing process becomes interesting for the Additive Manufacturing (AM) of complete, complex-shaped 3D parts with novel and outstanding characteristics.…”

Titanium Carbide Coating for Hafnium Hydride Neutron Control Rods: In Situ X-ray Diffraction Study

“…Moreover, carbides do not interact with liquid sodium at the specified temperatures. At present, TiC coating is well studied, and it is widely applied as a protective material [16][17][18][19][20]. Titanium carbide is also characterized by high resistance to radiation damage that can be beneficial for using it as a protective coating for nuclear applications [21][22][23].…”