1.1.2 Ni Mn binary alloy coating [6] Previous Next Stainless Steel Hex Bolts,Hexagon Screw Head,Heavy Hex Bolt,Hex Bolt Shaoxing Grace International Trade Co.,Ltd , https://www.shaoxinggrace.com
Metal manganese can increase the hardness, strength and wear resistance of nickel matrix than cobalt. The nickel-manganese carcass hardness is about 10 degrees higher than the nickel-cobalt carcass hardness. Although the content of manganese in the alloy is small, it has a great influence on the performance of the carcass. When the nickel-manganese carcass diamond drill bit is drilled in a hard and strong abrasive formation, the average life and aging are 55% and 30% higher than that of the nickel-cobalt drill bit, respectively. At the same time, the nickel-manganese carcass bit does not require high speed and pressure. Conducive to reducing material consumption and reducing drilling costs. However, the Ni Mn binary alloy coating has high brittleness and is easy to crack, which makes the working layer easy to be broken.
1.1.3 Ni Co Mn ternary alloy coating [7]
Ni Co Mn ternary alloy coating has higher comprehensive mechanical properties. The hardness is higher than Ni Co, and the brittleness is lower than Ni Mn.
It is in line with the requirements of the electroplated diamond products for the carcass. Stone tools made with Ni Co Mn ternary alloy coatings are sharper and more durable than Ni Co binary alloy coatings, especially for hard stone. The Ni Co Mn ternary alloy coating is low in cost due to the saving of a large amount of expensive material cobalt. The mechanical properties of the Ni Co Mn ternary alloy coating can be adjusted over a wide range to meet the needs of a wider range of applications. However, when the Ni Co Mn ternary alloy plating layer is obtained, the composition of the plating solution is complicated and the stability is not easily controlled.
1.2 Composite of carcass metal
The composite plating layer is a special plating layer formed by uniformly interposing one or several insoluble solid particles and fibers into a metal plating layer by a co-deposition method. Since the composite coating uniformly disperses a large amount of solid particles, these hard particles can greatly hinder the slip between the crystal grains, and the metal can be effectively strengthened.
1.2.1 Ni Co fine-grained diamond composite coating [8 10]
Adding an appropriate amount of nano-diamond powder to the plating solution, the hardness of the obtained Ni Co diamond composite coating is obviously improved, the hardness can reach 601.53 HV [8], and the friction and wear performance is remarkably improved: the friction coefficient of the nickel-cobalt alloy coating is about 0.35, and the life is When the friction radius is 14mm, the average is 0.022km; the friction coefficient of Ni Co diamond composite coating containing nano-diamond powder is about 0.3, and the coating life is 0.15km when the friction radius is 14mm [9]. The Ni Co diamond composite coating is used as the diamond bit matrix, and the prepared diamond bit is drilled in a hard and strong abrasive layer, which has good wear resistance, fast drill bit length, long service life and can prevent hole inclination [10]. Since the ultrafine diamond powder is extremely easy to agglomerate and its performance cannot be fully exerted, measures should be taken to disperse the diamond powder. This inevitably restricts the use value and application prospect of ultrafine powder.
1.2.2 Ni Co rare earth element composite coating [11]
The addition of a small amount of rare earth compound can improve the performance of the plating solution and the coating layer. In the electrodeposition process, the cation is mainly adsorbed on the surface of the metal deposit, and the rare earth metal ion exhibits strong adsorption on the electrode. The rare earth metal ions are easily adsorbed on the active point of crystal growth, that is, adsorbed on the growth point of the crystal plane, and the crystal growth is effectively suppressed. Therefore, after the rare earth element is added to the plating solution, a fine grain plating layer can be obtained. Using the universal cylindrical grinding machine M1420E through the grinding test of bright nickel plating and bright nickel plating diamond tool grinding with rare earth elements, it was found that the addition of rare earth elements improved the grinding ratio of the diamond tool. Bright nickel-plated diamond tools have poor wear resistance, fast consumption of the carcass, can not guarantee the high edge of diamond, and the diamonds fall off quickly; the bright nickel bond tool with rare earth added improves the wear resistance of the carcass, and the diamond package is better, the height of the diamond blade is high. Large, so the efficiency of the tool is improved.
1.2.3 Ni Co carbon nanotube composite coating [12-14]
Carbon nanotubes (CNTs) have superior strength and toughness and can be used as reinforcements for advanced composites to greatly improve the strength and toughness of composites. In addition, CNTs have the characteristics of good chemical stability and low friction factor, and it is expected to prepare a new type of composite coating with high wear resistance, wear reduction and corrosion resistance [13]. Observing the SEM morphology of the composite coating, the surface of the substrate is covered by a thick layer of carbon nanotubes. One end of these carbon nanotubes is deeply embedded in the matrix, and the other end is exposed to the outside of the substrate, which can obviously act on the substrate. Protection [14]. The laboratory is working on the preparation of electroplated diamond tools using this composite coating.