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The a-C:H coatings were deposited on AISI M2 steel disks using an unbalanced magnetron sputtering technique with a single titanium metal target, three graphite targets and mixed methane/ acetylene reactive gas. The various currents (9A-17A) were applied to the tungsten filament to enhance ionization rate of reactive gas. Tribological properties of a-C:H coatings were conducted used reciprocating friction tester. The results show that the tungsten filament current has a significant effect on the deposition rate, hardness and tribological properties of the coatings. With the increase of the tungsten filament current, the deposition rate and hardness of the coating increases, respectively. In sliding against an AISI 52100 steel ball for 24 minutes, all of coatings reduce the wear depth by a factor of at least 11 compared to that observed on an uncoated substrate. The 17A coating yields the best tribological properties that are the minimum wear depth, the lowest friction coefficient and the maximum lifetime when sliding against an AISI 52100 steel ball.

Carbon nitride coatings doped with tungsten were deposited on high speed steel disks by unbalanced DC magnetron sputtering using nitrogen-argon mixture gas. The coatings were deposited on three different types of interlayer (Ti, Ti/TiN and Ti/TiC), and the tungsten target current was varied from 0 to 0.9 A. Surface morphology of the coatings were measured by roughness testing and scanning electron microscopy (SEM). In addition, the chemical composition and depth profile were analyzed by X-ray Diffraction (XRD) analysis, Raman spectroscopy, and glow discharge spectroscopy (GDS). Finally, the hardness (H) and elasticity (E) were measured by nanoindentation and a Rockwell indentation test, while the tribological properties were tested using a pin-on-disk tribometer. After all, the coatings were measured by cutting testing of tuning inserts and micro-drillers. It is found that all of the coatings are amorphous and have a thickness of approximately 1.5 μm. Moreover, the nitrogen content is around 30 at%, while the tungsten content varies in the range of 0-9 at%. In addition, the hardness values are in the range of 15-20 GPa and the elasticity varies from 236 to 274 GPa. A good correlation is observed between the wear resistance and the indentation adhesion level. Furthermore, it is found that the hardness is not significantly correlated to the tungsten content and the coatings deposited on the Ti/TiC interlayer have greater adhesion. Finally, the coatings generally have a very low coefficient of friction (0.01-0.3) and a wear coefficient as low as 10-6 mm3/Nm, and the CN/TiC coating reduced 41% and 43% of flank wear in the cutting testing of turning inserts and micro-drillers respectively.

W(100-x)%Cx% coatings with different tungsten and carbon contents were deposited by unbalanced magnetron sputtering. The microstructures and mechanical properties of the W(100-x)%C x% coatings was characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), nanoindentation and adhesion testing techniques. The tribological performance of the coatings was investigated using a pin-on-disc trobometer under dry conditions. Experimental results indicated that coating microstructure, mechanical properties and wear resistance varied according to the tungsten and carbon contents of the coatings. The W72%C28% coating had the highest hardness/elastic modulus (H/E) ratio. In the ball-on-disc wear tests, it was found that the W72%C28% coating exhibited the best wear resistance.

A nanolayer WN/TiN coating was grown using an industrial-scale four-target reactive sputtering system. Effects of heat treatment on fundamental properties and wear performance of the nanolayer coating were studied. For comparison, a single layer TiN was used as a reference. Characterization was carried out using a nano hardness tester, GDOES, XRD and SEM. Wear performance was evaluated using an SRV® wear tester. It was found that the as-deposited nanolayer WN/TiN coating showed relatively high nano hardness and wear resistance as compared with the single layer TiN. The heat treatment resulted in performance degradation of the nanolayer coating. After 600 ℃ heat-treatment, the nanolayer coating showed very poor mechanical performance.

The Zr-C:H coatings with various C2H2 flow rate were deposited on micro-drills (a diameter of 0.2 mm) used a closed field unbalanced magnetron sputtering system. The ultrahigh speed (drilling speed of 160000 rpm) through-hole drilling printed circuit board tests used to evaluate the drilling performance of the coated micro-drills. The rejection criteria of service lives of the coated micro-drills were evaluated using two different criteria: (1) a nail head ratio greater than 1.5; (2) a drilled hole surface roughness greater than 25.4 μm. Adopting a service life criterion of a nail head ratio of 1.5, the Zr-C:H-5 coating possesses the optimal high-speed machining performance, which yields a micro-drill lifetime of above 6000 drilled holes. It represents a three-fold improvement on that of an uncoated micro-drill and it also improves machining quality.

The a-C:H:Zr-x coatings are deposited on micro-drills using a closed field unbalanced magnetron (CFUBM) sputtering system with pulsed-DC power frequencies in the range 30 kHz to 110 kHz (the x in the term a-C:H:Zr-x is the frequency varied in the deposition process). The hardness of the various coatings is systematically explored. Additionally, the machining performance of the coated micro-drills is investigated by conducting high-speed through-hole drilling tests utilizing Printed Circuit Board (PCB) specimens. The experimental results reveal that the a-C:H:Zr-70 coating has the highest hardness (42 GPa), while the a-C:H:Zr-110 coating has the lowest hardness (26 GPa). In addition, it is shown that the a-C:H:Zr-70 coating increases the life of the micro-drill by a factor of three compared to that of an uncoated micro-drill.

Lots of cutting heat is generated in milling process, and an unsteady temperature distribution is generated, which is the radical reason of impactive fracture and sticking-welding fracture of the tool. In this paper, the Cellular Automata model of regular gradient heat source on the rake face of milling insert is built using heat transfer theory and cutting principle to analyze the temperature field generated. The boundary condition of the insert is established and the unsteady temperature field of the insert is obtained using the Cellular Automata algorithm, which can be a basis for the direct reconstruction of the insert.

Radix salvia miltiorrhiza is a commonly used herbal medicine in China, and tanshinone IIA is one of the major active ingredients. Nano Radix salvia miltiorrhiza particles were successfully prepared by high speed centrifugal sheering (HSCS) technology, and the prepared nanoparticles suspension was subsequently spray-dried. The different properties of nano particles and raw powder were systematically studied by laser light scattering granulometric analyzer, TEM, SEM and FTIR. The extractive quantity of tanshinone IIA was determined by high-performance liquid chromatography (HPLC). The results illustrate that raw Radix salvia miltiorrhiza powder can be ultrafinely ground to nanosize within 50min, and the molecular structure of active ingredients doesn’t change after being ground. Furthermore, the active ingredients can dissolve out directly and fully, and the extractive ratio of tanshinone IIA increases 28.6% by HSCS processing. It is valuable to combine nanotechnology and TCM to improve the bioavailability and rapid releasing.

The Taguchi method was employed to analyse and optimise the use of TiCN films on cemented carbide (WC–6Co–10TiC–8TaC) indexable milling cutters with respect to machining conditions. Six variables, i.e. film construction, cutting speed, feedrate, depth of cut, workpiece hardness, and milling type, were considered. The results showed that the film construction was the most dominant variable, with a percentage contribution as high as 46·10% to the overall performance of the milling system. Through statistical calculation an optimal variable combination was obtained, and the optimal film construction was found to be 3 μm TiN + 2 μm TiCN (from the substrate to the surface) rather than 5 μm TiCN alone. The resultant flank wear showed 380 and 280% improvement over the uncoated and 5 μm TiN coated cutters respectively.

A cylinder-on-plate reciprocated sliding testing machine and a tension–compression testing machine were used to compare the wear, tension, and fatigue performance of specimens with Ti base and Cr base coatings grown by physical vapour deposition. Fracture mechanisms were examined using a scanning electron microscope and an optical microscope. The experimental results show that the Cr base coatings possessed far better wear resistance than the Ti base coatings. The application of surface films did not affect the Young's modulus and yield stress but did decrease the fracture strains somewhat. In the case of fatigue, the application of the surface coatings extended the endurance limit by 20–40 MPa.

Ceramic-coated steels (WC+12%Co and Cr3C2+ 25%NiCr applied by continuous detonation spraying, and Cr2O3applied by plasma spraying) were mated as sliding pairs to surface-treated steels (case hardened, tufftrided) under both dry wear and lubricated conditions in order to assess their tribological potential. Under dry wear conditions, WC-Co demonstrates the lowest coefficient of friction but surface-treated steels paired with Cr3C2-NiCr possess the best wear resistance under both dry wear and lubricated conditions. Five different types of generalized friction behavior were identified among the pairs studied. Under dry wear conditions, the worn surface of Cr3C2-NiCr is covered with continuous and “island”-transferred layers, while that of Cr2O3exhibits numerous cracks. The worn surface of WC-Co can be divided into four distinct regions, each possessing a major wear characteristic in addition to that of surface polishing. Wear mechanisms for TF1 surface-treated steels include surface polishing, strain fatigue and fracture of the work-hardened layer, while those for carburized steel include surface polishing, plastic deformation, material transfer and pile-up of back-transferred material. Under lubricated conditions, the amount of material transferred is reduced.

The Taguchi method was employed to analyze and optimize titanium carbonitride films on cemented carbide (WC-6% Co-10% TiC-8% TaC) indexable milling cutters with regard to machining conditions. Six variables— the films construction, cutting speed, feed rate, depth of cut, workpiece hardness and milling type—were considered. The results showed that the film construction was the most dominant variable, with a percentage contribution as high as 48.85% to the overall variance of the milling system. Through calculations an optimal film construction was found to be 3 μm TiN + 2 μm TiCN (from the substrate to the top) rather than 5 μm TiCN alone under the conditions specified in this study. The resultant flank wear achieved around 480% and 320% improvement compared with the uncoated and 5 μm TiN coated cutters.