Titanium Metal Matrix Composite Laser Coatings Based on Carbides

Abstract

Laser cladding is an adequate technique to fabricate Metal Matrix Composite (MMC) layers because of its focused high energy which allows the partial melting of hard ceramic reinforces particles like carbides. Thus, the wettability and gradual transition between metal and particle can be improved. However, metastable or new intermetallic phases can be formed during laser processing due to severe thermal cycle imposed to the clad with unknown properties in some cases. In this work our experience on microstructural analysis of Ti-MMC coatings acquired during the last five years is summarized. Special attention is paid on carbide dilution and secondary carbides formation mechanisms when TiC, SiC, Cr3C2, WC and B4C are mixed with titanium alloys.

INFLUENCE OF ZrB2 ADDITION ON MICROSTRUCTURAL DEVELOPMENT AND MICROHARDNESS OF Ti-SiC CLAD COATINGS ON Ti6Al4V SUBSTRATE

“…The dendrites are noticed to be densely populated showing an increase in compositional segregation and formation of new compounds. This also gives an enhanced effect on the metallurgical bond strength [26]. The surfaces of the SiC particles are observed to possess a degree of roughness which was not observed in the coating fabricated with no ZrB2 addition.…”

Structural Formation in the Zone of Interaction under Laser Processing of Bimetal M1 + VT1-0

“…Titanium alloys are prone to contact grasp during friction, regardless of the type and system of doping, as a result, to significant wear and mechanical damage to the contact surfaces. To improve tribotechnical properties of the parts made of titanium alloys, they typically use the same technologies for treating rubbing surfaces as for other metals: thermochemical treatment, electroplating, sputtering, laser and electric-spark surface doping, etc [3][4][5][6][7][8][9][10][11][12][13][14][15][16]. Analysis of studies in recent years, leads to the conclusion that traditional methods of increasing the wear resistance of products made of titanium and its alloys are ineffective.…”

Structure and wear resistance of Ti-TiC-TiB layers obtained by non-vacuum electron beam cladding

“…Recently, a lot of studies have been devoted to improving the tribotechnical properties of titanium alloys by the formation of composite coatings on their surface (TMC -titanium matrix composites) using laser and electron beam technologies [6][7][8][9][10][11][12][13][14]. Particles of carbides, borides, and silicides of metals act as hardening components in these materials.…”

“…In these studies great attention was paid to the processes of melting and crystallization of the materials, which have a significant effect on the structural-phase state and properties of the layers. The preparation of reinforcing particles in the cladded layers is possible with several approaches: the introduction of hardening particles directly into the melting metal [8][9][10][11] or the simultaneous melting of the surface layer of substrate material and the powder mixtures. When applying the first approach, the particles do not have enough time for dissolving in the base material and retain their original shape and size.…”