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Shen B.,Shanghai JiaoTong University | Sun F.H.,Shanghai JiaoTong University | Zhang Z.M.,Shanghai Jiaoyou Diamond Coating Co.
Key Engineering Materials | Year: 2011

The tribological performance of conventional microcrystalline diamond (MCD) film and diamond-like carbon (DLC) film is investigated comparatively under water lubricating condition. The MCD and DLC film are deposited on cobalt cemented tungsten carbide (WC-Co) substrate using the hot filament chemical vapor deposition (HFCVD) method and the vacuum arc discharge with a graphite cathode respectively. Scanning electron microscopy (SEM), white light interferometer, and Raman spectra are employed to characterize as-deposited MCD and DLC samples. The friction tests are carried out on a ball-on-plate reciprocating friction tester, where the sliding process is conducted under water lubricating condition. Silicon nitride, tungsten carbide, ball-bearing steel and copper are used as counterpart materials. The results indicate that DLC film always exhibits lower friction coefficient than MCD film under water lubricating condition, except the case of sliding against the silicon nitride, in which DLC film is worn out very rapidly and thus leads to the high friction coefficient. The wear resistance of DLC film under water lubricating condition is significantly poorer than that of MCD film. While sliding against silicon nitride, tungsten carbide, ball-bearing steel and copper, its wear rate is calculated as 3.67×10-7 mm3N-1m -1, 9.31×10-9 mm3N-1m -1, 3.54×10-7 mm3N-1m -1, and 4.97×10-8 mm3N-1m -1 respectively. Comparatively, no measurable wear track can be found on the worn surface of MCD films. © (2011) Trans Tech Publications. Source


Shen B.,Shanghai JiaoTong University | Sun F.,Shanghai Jiaoyou Diamond Coating Co.
Solid State Phenomena | Year: 2011

Micro/nano-crystalline multilayered ultra-smooth diamond (USCD) films are deposited on the interior-hole surface of conventional WC-Co drawing dies with a combined process consisting of the hot filament chemical vapor deposition (HFCVD) method and polishing technique. Scanning electron microscopy (SEM), surface profilemeter, Raman spectroscopy and X-ray diffraction (XRD) are employed to provide a characterization of as-deposited USCD films. The results exhibit that as-deposited USCD films present an ultra-smooth surface, its surface roughness values (Ra) in the entry zone, drawing zone and bearing zone are measured as 25.7 nm, 23.3 nm and 25.5 nm respectively. Furthermore, the working lifetime and performance of as-fabricated USCD coated drawing dies are examined in producing copper tubes with hollow sinking, fixed plug and floating plug. The results show that the lifetime of USCD coated drawing is as more than 30 times as that of WC-Co drawing dies in the drawing process with hollow sinking, 7 times in the fixed plug drawing and 10 times in the floating drawing .© (2011) Trans Tech Publications, Switzerland. Source


Bian L.J.,Shanghai JiaoTong University | Lin Z.C.,Shanghai JiaoTong University | Sun F.H.,Shanghai JiaoTong University | Guo S.S.,Shanghai Jiaoyou Diamond Coating Co.
Applied Mechanics and Materials | Year: 2012

The shaped-wire drawing dies are used more and more popularly in the metal product industry for several advantages of locked structure. In present investigation, a layer of CVD diamond film is deposited on the interior-hole surface of shaped-wire drawing die using a hot filament chemical vapor deposition (HFCVD) method, followed by a surface polishing process, aiming at further prolonging its working lifetime of shaped-wire drawing dies and improving the surface quality of produced wires. The scanning electron microscopy (SEM), surface profiler and Raman spectroscopy are adopted to present the characterization of both as-deposited CVD diamond films before and after polishing. Furthermore, the performance of as-fabricated CVD diamond coated drawing dies is examined in the practical production process. The results show that as-deposited CVD diamond films are homogeneous and the working surface is smoother after polishing. Comparing with the conventional shaped drawing dies, the working lifetime of the diamond coated shaped-wire drawing dies can be increased by a factor of above 10, and the shaped wires with higher surface quality can be obtained. © (2012) Trans Tech Publications, Switzerland. Source


Shen B.,Shanghai JiaoTong University | Sun F.-H.,Shanghai JiaoTong University | Zhang Z.-M.,Shanghai Jiaoyou Diamond Coating Co. | Shen H.-S.,Shanghai Jiaoyou Diamond Coating Co. | Guo S.-S.,Shanghai Jiaoyou Diamond Coating Co.
Transactions of Nonferrous Metals Society of China (English Edition) | Year: 2013

A specific revised HFCVD apparatus and a novel process combining HFCVD and polishing technique were presented to deposit the micro- and nano-crystalline multilayered ultra-smooth diamond (USCD) film on the interior-hole surface of WC-Co drawing dies with aperture ranging from d1.0 mm to 60 mm. Characterization results indicate that the surface roughness values (Ra) in the entry zone, drawing zone and bearing zone of as-fabricated USCD coated drawing die were measured as low as 25.7, 23.3 and 25.5 nm, respectively. Furthermore, the friction properties of USCD films were examined in both dry sliding and water-lubricating conditions, and the results show that the USCD film presents much superior friction properties. Its friction coefficients against ball-bearing steel, copper and silicon nitride balls (d4 mm), is always lower than that of microcrystalline diamond (MCD) or WC-Co sample, regardless of the lubricating condition. Meanwhile, it still presents competitive wear resistance with the MCD films. Finally, the working lifetime and performance of as-fabricated USCD coated drawing dies were examined under producing low-carbon steel pipes in dry-sliding and water-lubricating conditions. Under the water-lubricating drawing condition, its production significantly increases by about 20 times compared with the conventional WC-Co drawing dies. © 2013 The Nonferrous Metals Society of China. Source


Lin Z.C.,Shanghai JiaoTong University | Sun F.H.,Shanghai JiaoTong University | Zhang Z.M.,Shanghai Jiaoyou Diamond Coating Co. | Shen H.S.,Shanghai Jiaoyou Diamond Coating Co. | Guo S.S.,Shanghai Jiaoyou Diamond Coating Co.
Materials Science Forum | Year: 2014

Diamond-coated drawing dies are considered as ideal drawing dies for their unique characteristics, such as high hardness, wear resistance and low friction. To utilize the superior characteristics of diamond coatings, the FEM simulation is used to simulate the copper strip cold drawing process. The stress and the drawing load are predicted. The influence of parameters of drawing process on the drawing load is investigated. The optimal parameters are obtained. © (2014) Trans Tech Publications, Switzerland. Source

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