Preparation of Ti-coated diamond particles by microwave heating

A Review of the Diamond Retention Capacity of Metal Bond Matrices

“…Consequently, the diamond retention capacity mainly depends on the mechanical inlaying force for general metal-bonded diamond tools, causing a weak bonding strength between diamonds and matrix [21]. For this reason, the diamond grains easily fall out of the matrix in the working process, which ultimately reduces the utilization and service life of diamond tools [22].…”

“…As a result, the intermediary role of the coated layer creates the strong bonding between diamond and matrix. Many methods are used to achieve diamond surface metallization, such as physical vapor deposition, chemical vapor deposition, vacuum slowly vapor deposition, molten salt method, magnetron sputtering, and laser cladding [22]. The theory of diamond surface metallization is based on the formation of a carbide layer due to the intense interfacial chemical reaction between diamond and strong carbide-forming elements under the appropriate process conditions.…”

“…Similar to diamond surface metallization, the strong carbide forming elements added in matrix powders can also form a transition carbide layer between the bonding matrix and the diamond grits during the process of heat treatment or sintering [38,39], thereby combining the diamond grits with the metal matrix metallurgically [22]. Away from this interfacial layer, various intermetallic compounds precipitate in the bonding matrix, further alleviating the interfacial stress associated with a mismatch in the thermal expansion coefficient and phase transformation during cooling [40].…”

Microwave-Assisted Molten-Salt Facile Synthesis of Chromium Carbide (Cr3C2) Coatings on the Diamond Particles

“…In order to improve the adhesive force between the metal layer and the diamond, several diamond surface metallization approaches, such as dc magnetron sputtering technique, electroless plating, electroplating, vacuum micro-deposition technology, vacuum plating, and salt bath plating, have been reported in recent years [5,[9][10][11][12]. Active elements, such as Cr, B, Ti, Mo, and W, are coated on the surface of diamond particles before sintering and infiltration to improve the interface bonding property diamond/metal composites [2,[12][13][14][15][16][17][18][19][20][21][22][23]. These metal elements can act as middle layers that strengthen the interface and protect the diamond powder from the atmosphere and reduce the degree of graphitization at high temperatures.…”

“…Although the copper-diamond composites with chromium carbide coatings on diamond particles by vacuum pressure infiltration, spark plasma sintering technique, or conventional sintering method [12,17,46,47], silicon carbide coating on the diamond particles [48], TiC coating on the diamond particles [20] by microwave heating have been reported; and silicon carbide (SiC)-coated graphite composite powders was synthesized using graphite flakes and silicon powders as raw materials by the microwave-assisted molten salt synthesis [49], there has been little discussion about the chromium carbide coatings on the diamond particles by microwave sintering process in a molten salt mixture.…”