Microstructure and properties of a titanium carbide reinforced coating on grey iron applied with laser cladding

Abstract

A titanium carbide (TiC) reinforced Fe-based composite coating was prepared with laser cladding using titanium powder as the added material on grey cast iron. The macroscopic morphology and microstructure of the coating were analyzed; the hardness and wear resistance of the coating were investigated. The results show that a good coating was produced, without any cracks and porosity. The graphite phase disappeared and the TiC phase appeared in the coating after the laser-cladding process. A static melting zone without TiC and graphite appeared between the cladding zone and the substrate. With the formation of fine TiC particles, the average microhardness of the coating rose up by more than 3 times compared to the substrate material, and the coating exhibited good wear resistance.

Effect of Chromium and Molybdenum Addition on the Microstructure of In Situ TiC-Reinforced Composite Surface Layers Fabricated on Ductile Cast Iron by Laser Alloying

“…High C contents in cast iron substrates provide excellent conditions for the in situ formation of MMC surface layers via LA, with elements that tend to form carbides. Several studies on the LA of cast iron substrates have focused on the in situ synthesis of TiC-reinforced layers (TRLs) by introducing Ti into the molten pool [ 16 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ]. From the point of view of the wear properties, the microstructure of the synthesized TRLs should contain a martensitic matrix with homogeneously-dispersed TiC precipitates [ 24 , 26 ].…”

“…Several studies on the LA of cast iron substrates have focused on the in situ synthesis of TiC-reinforced layers (TRLs) by introducing Ti into the molten pool [ 16 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ]. From the point of view of the wear properties, the microstructure of the synthesized TRLs should contain a martensitic matrix with homogeneously-dispersed TiC precipitates [ 24 , 26 ]. Moreover, published data on the wear performance of Fe-based MMCs reinforced with TiC phase suggest a significant increase in the wear resistance of TRLs with increasing the TiC fraction [ 24 , 26 , 27 , 28 , 29 ].…”

“…From the point of view of the wear properties, the microstructure of the synthesized TRLs should contain a martensitic matrix with homogeneously-dispersed TiC precipitates [ 24 , 26 ]. Moreover, published data on the wear performance of Fe-based MMCs reinforced with TiC phase suggest a significant increase in the wear resistance of TRLs with increasing the TiC fraction [ 24 , 26 , 27 , 28 , 29 ]. However, reported works have shown that during the in situ synthesis of TRLs on cast iron substrates via LA, it is difficult to maintain a homogeneous dispersion of the reinforcing phase upon increasing the Ti concentration in the melt [ 23 ].…”