Advanced Materials Research Vols. 538-541

Abstract: Discuss a way of using the CAD/ CAM technology to process nonlinear space surface. By analyzing the processing of nonlinear space surface, the nonlinear space surface machining process plan was determined. The fine model and program was finished by innovative using of combination modeling method in UG. Many key technical problems such as surface finish, work fixture were solved in the process of dealing with CAD/CAM of nonlinear space surface, acceptable product was made on common milling machine by using post-processing NC coding,. The process plan improved machining precision and shortened the production cycle，a good results have been obtained.

Abstract: Zn-Al filler metal wettability tests were performed. With the match of CsF-AlF3 flux, Zn-Al filler metal wettability is poor on pure copper surface. The Cu-Al-Zn intermetallic compound interface layer exits between Zn-Al filler metal and Cu base metal. When Al content is low in Zn-Al filler metal, the filler metal wettability is poor and the filler metal melting point is low. In the wettability test course, the time is long in which Cu base metal interacts with liquid Zn-Al filler metal. And the Cu-Al-Zn intermetallic compound interface layer grows thick between filler metal and base metal. With the increase of Al content in Zn-Al filler metal, the interaction strengthens between Zn-Al filler metal and Cu base metal. In the wettability test course, the time beocome short in which Cu base metal interacts with liquid Zn-Al filler metal. The Cu-Al-Zn intermetallic compound interface layer gets thin between filler metal and base metal. Meanwhile, Zn-Al filler metal wettability improves on pure copper surface. But the improvement is not remarkable. Its wettablility is still poor on pure copper surface.

Abstract: WC-10Co-4Cr cermet coatings were deposited on Inconel 718 alloy using the HVOF technique, then were heat treated by isothermal treatment (500°C, 3hours). The influences of isothermal heat treatment on micro-hardness, fracture toughness and abrasive wear resistance of WC coating were studied in this paper. The results show that the micro-hardness and fracture toughness of WC coating decrease after isothermal heat treatment, then the metallic blinder breaks up and the tungsten carbide particles pull out during abrasive wear test. Finally, it was concluded that the abrasive wear resistance of WC-10Co-4Cr coating decreased after isothermal heat treatment (500°C, 3hours).

Abstract: In order to improve the wear resistance and extend service life of aluminum alloy parts, the Ni-base alloy anti-wear coatings were prepared on the surfaces of 7A05 aluminum alloy by plasma spraying technology. The microstructure and interface of the coatings were analyzed, and the friction and wear properties of Ni-base alloy coatings and aluminum alloy substrates were investigated under dry friction condition at room temperature. The research results show that the main phases of Ni-base alloy coating are γ-Ni, CrB and Cr23C6. The thicknesses of diffusion layers existing between intermediate layer and coating, intermediate layer and substrate are respectively 15μm and 20μm. The bonding types of the coating and the substrate are mechanical combination accompanied with partially metallurgical combination. When wore against GCr15 steel balls, the average friction coefficient of the Ni-base alloy coatings is 11.6% lower than that of the aluminum alloy substrates, and the average wear loss of the former is 9.3mg, which is only 1/3 of that of the latter. With the increase of loads, the wear mechanisms of the Ni-base alloy coatings change from slightly micro-cutting wear and fatigue wear to abrasive wear and micro-fracture wear, while those of the aluminum alloy substrates are mainly adhesive wear and abrasive wear as well as slight oxidation wear.

Abstract: The surface modification of superfine brucite using silane coupling agent as a modifier was studied. The results of the best modified conditions show that the treated time is 1.5h, the treated temperature is 40°C, the content of silane coupling agent is 7wt%,the stirring speed is 600r/min. In this condition, the activation index up to 93.5%; the treated brucite particles filled into polypropylene(PP), the best tensile strength of 28.63MPa and the LOI of 30% is measured.

Abstract: The Ni-P-Sn coatings were prepared by electroless plating. Crystallization fouling adhering experiments indicated that these electroless Ni-P-Sn coatings have better anti-fouling property than that of un-coated and Ni-P samples. The surface free energy of Ni-P-Sn deposit increases with the increase of the nanocrystalline phase. It’s considered that the degree of crystallization fouling adhesion is related to the surface free energy of the sample. The amorphous matrix with lower surface free energy can significantly improve the anti-fouling ability in comparison with that of un-coated samples.

Abstract: Paper plays an important role in determining image quality in inkjet printing. For high print quality, halftone dots should have minimal dot gain and sharp, circular edges, the receiving surface must have a line, high-porosity structure and be hydrophilic. Paper structure and surface chemistry requirements for good inkjet print quality are so unconventional that new paper grades for inkjet printing should be specially designed. This paper discuses the impact of coating adhesive on printability of inkjet paper.

Abstract: The bionic surfaces with convex domes were designed based on the bionic tribology. Using the self-made test-bed for measuring the plane friction coefficient, the friction coefficients between the samples and the belt were measured. The belt’s type used for tests is NN-100 and its number of plies is three, as a fixed contact surface. The samples consisted of the convex dome with spherical crown, convex cylinder and smooth rubber surface as a comparative sample as well. The influences of the press, temperature and loading time on the friction performance of the bionic surface with convex dome were analyzed by the friction coefficient in the different conditions. Compared with the measuring result of the smooth rubber surface, the increasing-friction effect of the bionic surface is analyzed and the influences on the bionic surface from the factors mentioned above are examined if they are the same with those on the smooth surface. According to the test results, the influences on the friction performance from the shape, dimension and hardness of the convex dome are discussed and the increasing-friction mechanism is analyzed.

Abstract: To improve the corrosion resistance of Al alloy, triethylamine (TEN) was added into the sealing solutions. Tafel polarization and electrochemical impedance spectroscopy(EIS) techniques were used to investigate the electrochemical behavior of sealing coatings formed in different concentrations of triethylamine(TEN). Compared with the coatings with D. I. water and the bare aluminum alloy, the polarization curves show that the sealing coatings formed in 5.0 – 7 .0 g.L-1 triethylamine (TEN) solutions have more positive corrosion potential (Ecorr) and pitting corrosion potential (Epit), and lower corrosion current density (icorr). Electrochemical parameters of EIS indicate that the sealing coatings have higher corrosion resistance. The electrochemical test results show the prepared sealing coatings have better corrosion resistance.

Abstract: Al₂O₃ and Al₂O₃-40wt.%TiO₂ ceramic coatings on H13 hot-worked die steel have been prepared by plasma spraying, and then the microstructure, micro-hardness as well as wear resistance of the prepared coatings have been investigated by means of x-ray diffraction (XRD), scanning electron microscope (SEM), Vickers hardness tester and ball-on-disk high temperature tribometer. The results showed that the plasma sprayed ceramic coatings are of higher hardness and wear resistance than H13 hot-worked die steel.