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Cutting Tools
Published in Hassan El-Hofy, Fundamentals of Machining Processes, 2018
Diamond: Polycrystalline diamond, manufactured by sintering under high pressure and temperature, is now available as a cutting tool material. Because diamond is a pure carbon, it has an affinity for the carbon contained in ferrous materials. Artificial diamond has proved to be far superior to natural diamond for machining nonferrous alloys and abrasive materials such as pre-sintered carbides and ceramics, as well as graphite and high-silicon aluminum alloys. Diamond tools should be used for finish turning and boring of cast iron, aluminum and its alloys, magnesium alloys, bronze, gold, silver, rubber, and plastic, at speeds ranging from 100 to 2,000 m/min. Diamond tools are costly and are therefore restricted to turning operations and the dressing of grinding wheels.
Cutting And Wear Applications
Published in Mark A. Prelas, Galina Popovici, Louis K. Bigelow, Handbook of Industrial Diamonds and Diamond Films, 2018
Single-crystal diamond tools, natural or synthetic, are still in use because extremely sharp cutting edges and very low-friction surfaces are attainable with these tools. These properties allow them to impart extremely fine surface finishes to lens in the optics industry. Single-crystal diamonds have cleavage planes allowing them to fracture rather easily along these planes. Cleavage-plane orientation relative to the cutting forces is extremely critical to a single crystal diamond tool’s performance. Compacted sintered PCD, CVD diamond film, and CVD diamond sheet on the other hand are polycrystalline and are relatively isotropic, so that crystallographic orientation is a less important factor than in single crystal tools [Field and Pickles 1996].
Influence of tungsten coating on microstructure and thermal damage of brazed diamonds
Published in Surface Engineering, 2019
Fan Liu, Yang Yang, Bingsuo Pan
Industrial diamond tools are widely used in the processing of stone, ceramics and other hard materials, as diamond has the highest hardness, good wear resistance and low friction coefficient. Brazed diamond tools have shown outstanding performance in different applications because there is metallurgical bonding between diamond grains and brazing alloy [1,2]. Various filler alloys, such as Ni-based and Cu-based alloys [3,4], are commonly used to braze diamond grains onto steel substrates. Ni-based alloy is a favourable matrix material for its greater strength and wear resistance. However, Ni-based brazing is generally carried out at a temperature of about 1000°C, which usually causes severe thermal damage to diamond grains (i.e. graphitization under the catalytic effect of nickel, chemical erosion by chromium). As a result, the weakened diamond strength degrades the cutting performance of Ni-based brazed tools.
Laser power effects on properties of laser brazing diamond coating
Published in Surface Engineering, 2020
Weimin Long, Dashuang Liu, Xian Dong, Aiping Wu
Diamond tool is widely used to machine hard and brittle materials, such as cemented carbide, engineering ceramics, glass, sapphire and stone, owing to its highest hardness, rigidity, good abrasion resistance, corrosion resistance and chemical stability among natural substances since the crystal structure of diamond is unique [1–3]. However, due to the limitation of diamond manufacturing technology, the size of single-grain diamond is small. It may bring difficulties to the direct use of diamond since the diamond is supplied in the form of fine particles or even fine powders. Thus, diamond tool is usually fabricated by joining diamond to metal matrix. The excellent performance of diamond tool is mainly contributed to the bonding properties between diamond and matrix.
Properties of nano-SiC/Ni composite coating on diamond surfaces
Published in Surface Engineering, 2018
Diamond is the hardest material on the earth and it can be used to make abrasive tools, which have the following advantages: high grinding efficiency, low grinding force, high wear resistance, long dressing period, and low comprehensive cost. Diamond tools are composed of diamond grits and a matrix bonding material. Polymers, ceramics, and alloys are currently used as matrix bonding materials. Among these three categories of bonding agents, metal-bonded diamond tools have the appropriate hardness, strength, and are easy to mould. Therefore, metal-bonded diamond tools are utilised extensively for cutting, drilling, and surface grinding of stones, concrete, advanced ceramics, and cemented carbides. However, due to the high interfacial energy between diamond and alloys, it is very difficult to make diamond efficiently embed in metal matrices. Poor bonding results in the dropping of diamond grits from metal matrices during grinding and cutting and thus the bond strength between diamond grits and metal matrices is one of the key factors to control the properties and life span of a tool. Studies have shown that coating diamond surfaces is an effective method to improve the mechanical properties between diamond and metal matrices [1, 2]. Additionally, nanoparticles can be used in composite coatings to enhance mechanical, wear, and corrosion properties [3–6]. As a result, much attention has been given to composite electroplating. Recently, Ni-based composite coatings with the addition of nanoparticles such as Al2O3, SiO2, SiC, Si3N4, and diamond have been prepared by brush plating and shown increased performance with higher hardness, wear resistance, and corrosion resistance [5–12]. However, until now, the study of ceramic nanoparticles and Ni composite plating on diamond surfaces has not been conducted.