Advanced Materials Research Vols. 690-693

Abstract: The study on combinatorial additives and plating technics for preparation and apply Ni-Co-P alloy coating was carried out completely, and the Ni-Co-P alloy with functional, corrosion-resistance and ornamental multicomponents was found, the optimum technics of plating multicomponents alloy was been found. The coating made in optimum technics was good in corrosion-resistance and wear-resistance, and with a smooth, fine, shining surface. It was proved by determinations that the 8.2% phosphorus in the coating and the coating was amorphous crystal. It was found that the combination force between the substrate and coating was very good, the corrosion-resistance and abrasion-resistance of coating were much better than that of Ni-P alloy according to the examination, the Ni-Co-P alloy coating with special character which were good magnetic properties and finery in ornamentally also.

Abstract: Electroless deposition technique was used to coat Ni-P on TiB₂ particles by activating the TiB₂ powder in a furnace at 400 ^◦C for 1 h. Scanning electron microscopy images and EDS spectra before and after electroless nickel plating confirm that nickel is deposited on the surface of TiB₂ particles. With the increase of heat treatment temperature, coating weight is increased firstly and then decreased, and reached the maximum value at 400 ^◦C. XRD results show that the Ni-P deposit was predominantly amorphous. However, after heat treatment, the metallic deposits can easily transform into crystalline Ni and Ni₃P phases, as confirmed by DSC and XRD analyses.

Abstract: Cr-C coatings with gradient Cr/CrN/CrCN inter-layers were studied to elucidate the effects of carbon contained on the mechanical properties and microstructures of the deposited coatings. The coatings were deposited by using a reactive sputtering system with constant total flow rate, target current and substrate bias. Percentage of C₂H₂ flow rates were varied from 10 % to 50 %. Carbon contains in the film were measure by EDS. Mechanical properties of the coatings were evaluated with micro-indentation, scratch tester, ball-on-disk tribo-tester. Microstructures of the films were characterized by SEM, TEM, and X-ray diffractermeter. The experimental results show that carbon contain increase from 21.6 %to 99.5 % with respect to C₂H₂ flow rates varied from 10 %, 20 %, 30 %, 40 %, 50%. And the phase of coatings change from Cr solid solution to Cr+Cr₂₃C₆+ amorphous diamond like carbon (DLC) and then to DLC +Cr₇C₃ and then to DLC+ Cr₃C₂+Cr₇C₃. The hardness of the coatings increase with C₂H₂ flow rate increased and achieved the maximum value of Hv1815 at 50% C₂H₂ flow rate. The coefficient of friction decreases from 0.630 to 0.285 when C₂H₂ flow rate increased from 10% to 50%. The wear rate decreased with increasing the C₂H₂ flow rate.

Abstract: As excellent performance coating material, the TiAlN coating has become alternative to TiN coating, with a very broad application prospects. We calculated the lattice constants, elastic parameters, electronic constants of Ti_1-xAl_xN. Its elastic constants trend was downward as the Al element contents increasing, and its brittleness fell. We had analysed the band structure and density of states of TiA1N, and TiA1N was illustrated to be conductor.

Abstract: The Ti (C, N)/Al₂O₃ composite coating was prepared on surface of YT15 cemented carbide by using electro-spark deposition process. The surface morphology, energy spectrum analysis and microhardness of the coating were investigated, and the cutting forces and wear resistance of the tools with and without Ti (C, N)/Al₂O₃ composite coating were studied by cutting tests. The results show that the microhardness of the YT15 cemented carbide with Ti (C, N)/Al₂O₃ composite coating increased 181Hv, and the coating tools had better wear resistance and lower cutting force.

Abstract: In order to remove the cutting marks on the cutting surface of 6H-SiC single crystal wafer, experiments were conducted to investigate the effect of the abrasive characteristics (types, grain size, concentration and mixed abrasives) on the lapping performance of 6H-SiC single crystal wafer, then the removal mechanism of the abrasive grains in the lapping process was studied. Results indicate that the abrasives with larger grain size and higher hardness can result in a higher material removal rate while the abrasives with smaller grain size and lower hardness can achieve a lower surface roughness value. When the concentration of the abrasives is 7.69 wt%, a good lapping effect was obtained. Lower surface roughness value Ra can be obtained with a high material removal rate by using certain proportion mixed abrasives. Selecting appropriate abrasives can obtain a high surface quality of 6H-SiC wafer with a high efficiency.

Abstract: The magnetic polymer ICF targets are fabricated by depositing the Ni-P coats on the surface of polystyrene microsphere using the electroless plating. The microstructur of the coat, and the magnetic property, surface roughness and sphericity of the magnetic microsphere were examined and analyzed, resperctively. The results indicated the examined indexes can basically meet the requirements of ICF targets.

Abstract: The effects of the microstructure properties on the mechanical properties of C-Si-Mn hot rolled dual phase steel are reported. It was observed that both the amounts of the martensite and the particle size of the ferrite significantly influence the mechanical properties of hot rolled dual phase steel. The aim of our works is to develop a modeling method for controlling the microstructure properties of C-Si-Mn hot rolled dual phase steel through the experimental trend comparison of the aforementioned two factors on their mechanical properties.

Abstract: In this paper, first of all quality requirements of the large automobile stamping was introduced. Based on investigation, the main failure forms of species and its related influencing factors were determined, and analyzed the stamping wrinkling and cracking mechanism of failure modes. Finally the corresponding countermeasure was proposed. The paper can provide valuable referenced for domestic research institutes and automobile production enterprises.

Abstract: The FEM model of radial-axial ring rolling experimental equipment was established by using ANSYS through processing contact, constraints and loads. The structure stiffness and strength of both radial rolling system and axial rolling system were analyzed based on the analyses of distributions of Von Misese stress, equivalent strain and deformation. It is shown that both the two systems will be within the safe range without any plastic deformation during ring rolling process, and their stiffness is also satisfied with design requirement, which proves the successful design of the radial-axial ring rolling experimental equipment.