Papers by Keyword: Ion Plating

Abstract: Diamond-like-carbon (DLC) films are promising as coating materials. Ion plating, an excellent method in terms of adhesiveness, step coverage, and deposition rate, can form not only pure metal films but also oxide films, nitride films, and carbonized films. In this study, which aimed to form a DLC film with good adhesiveness and a diamond crystal structure, a DLC film, with a SiC interlayer formed by ion plating with introduction of tetramethylsilane (TMS), was formed. It was experimentally revealed that as the interlayer thickness increases, the crystal structure in the DLC film becomes more diamond rich, and the adhesiveness of the DLC film and substrate is thereby improved.

Abstract: Knowing temperatures at the tool-chip interface is extremely important to optimize the machining condition and to improve the machining performance, furthermore to design high performance materials. In order to grasp the temperature distribution at the tool-chip interface, this study has devised an indexable insert with seven pairs of built-in micro Cu/Ni thermocouples on the rake face near the cutting edge. This paper shows the performance of the indexable insert with built-in micro thermocouples developed. The thickness of each element of the micro thermocouple is approximately 15 μm. The result of unsteady heat conduction analysis employing FEM shows that the temperature difference by installing the micro thermocouples is less than 10 K or 1.2 %. The temperature measurement experiments by cutting of aluminum alloy were carried out by changing the cutting speed. The results provided the evidence that the temperature distribution at the tool-chip interface can be grasped with the indexable insert with built-in micro thermocouples developed.

Abstract: It is known that during the cutting process the tool wears out. This is due to the high temperatures, the relative velocities and shocks between the contact surfaces of the tool-part and the mechanical and thermal stresses which appear on the active surfaces of the tool. The result is loss of cutting and reduced processing quality. This involves taking measures to increase the values of the cutting tools and/or the durability of their cutting inserts. Tool durability can be increased by various coating methods by the depositing in a vacuum of some different materials which achieve the necessary effect. These methods are being researched globally. So far there are several methods of applying these layers. They are classified as: vacuum thermal evaporation, pulverization, ion plating and chemical vapor depositing. In order to increase the durability of the cutting tools, and to increase the wear resistance of the metal carbide insert, the authors propose in this paper the depositing of a titanium thin layer on these cutting inserts by the ionic plating method. This method has produced increased durability of the coated cutting insert and increased resistance to wear, higher than in the uncoated case. The values slightly vary depending on the complexity of the cutting insert profile and the dimensions of the work pieces dimensions being processed.

Abstract: It is known that the unevenness of the cutting depths during the cutting processes, the different physico-mechanical characteristics of the processed materials, values as well as the parameters variation of the working regimes can lead a wear more or less pronounced of the used cutting tools. The lubricant presence in the cutting area may contribute to the friction and thermal field values reduction, affecting the wear processes. It can be said therefore that, the tools durability is influenced by all these factors, which requires decisions and actions to reduce the tools or/and the cutting inserts wear processes. In case of the cutting inserts are known many researches concerning their coverage with material (ions) by vacuum deposition, using methods as: electric arc evaporation, pulverization, ionic plating and chemical vapor deposition. Researches carried out by authors had consisted in making titanium deposition, in thin layer, on the cutting inserts surface in their hardening purpose. The results obtained consisted in a substantial increase of the durability for the used tools in cutting processes in report to those, whose cutting inserts were coated with titanium.

Abstract: The CrAlN composite coatings with different Al content are deposited on 65Mn steel substrate by multi-ion plating technology. The structure, surface morphology, composition and oxidation resistance of CrAlN composite coatings are tested by XRD, EDS, SEM and oxidation furnace, respectively. The experimental results show that the preferential growth orientation of the coatings was changed from CrN (111) to CrN (200) after the addition of Al element. And the surface roughness of CrAlN coatings increase gradually with increasing of Al content. Compared with CrN coatings, the CrAlN composite coatings show much better oxidation resistance. And the oxidation resistance ability will enhance with increasing Al content, because Al and Cr oxide form after oxidation in high temperature condition which could reduce the diffusivity ability of oxygen.

Abstract: By using the ion plating technology,the multilayered CrN/TiAlN as well as monolayered CrN and TiAlN coatings were made on the suface of piston rings to improve its tribological properties and increase service life using Cr and Ti50Al50 alloy cathodes. EDS analysis showed that the main compositions of CrN/TiAlN coatings are Cr30.61%,Ti 20.42%,Al 13.88% and N 35.10%. The preferred orientation was changed from (111) in CrN and TiAlN monolayered coatings to (220) plane in the multilayered CrN/TiAlN coatings. The multilayered CrN/TiAlN coatings had smaller crystallite size than the monolayered CrN coatings. The multilayered TiAlN/CrN coating with rotational speed at 1.5 rpm exhibited the highest H3/E2 ratio value of 0.23 GPa, indicating the best resistance to plastic deformation, among the studied CrN, TiAlN and multilayered TiAlN/ CrN coatings. The CrAlTiN composite films performs better than binary CrN as well as the Cr plating in teams of hardness and wear resistance at high temperature.

Abstract: Precipitation-strengthened Cu-based alloys have limited use as structural materials at high temperatures due to precipitate coarsening and strength loss. We have recently shown that Curefractory metal alloys produced by various physical vapor deposition methods have stable, nanocrystalline microstructures and maintain their strength properties even when annealed at temperatures as high as 900 C for up to 100 hours. This paper presents discussions of how these alloys are processed and the resulting microstructures. X-ray and electron microscopy results will be presented to document the phase transformations that occur in these alloys and result in such exceptionally stable microstructures.