Advanced Materials Research Vols. 941-944

Abstract: A numerical study using finite element analysis (FEA) was performed to investigate the thermal, shear and radial stresses developed in MAO coating on substrate of TC4 under thermal cycle loading. The four-node quadrilateral thermal solid element PLANE55 and four-node quadrilateral structural solid element PLANE42 with axisymmetric option was used to model the temperature distribution and thermal stress field of the MAO coating on TC4 substrates. The thermal stress, radial stress and shear stress along the thickness in film/substrate system are analyzed systematically under different thermal cycle loading. It is found that the thermal stress of MAO coating exhibits a linear relationship with thickness of substrate, but it exhibit a parabolic relationship with the thickness of the coating. The radial stress and shear stress distribution of the coating–substrate combination are also calculated. It is observed that high tensile shear stress of MAO coating on TC4 substrate reduces its adhesive strength but high-compressive shear stress improves its adhesive strength.

Abstract: Al (OH)₃ coated CaF₂ composite powder was prepared by coating Al (OH)₃ on surface of micro-sized CaF₂ particles using heterogeneous nucleation method. Influence of Al³⁺ concentration, PH value and reaction temperature was studied. The result reveals that CaF₂ particle was uniformly coated with a layer of Al (OH)₃ and Al³⁺ concentration, pH value and reaction temperature are the main factors that affect coating result. Optimum technological conditions are Al³⁺ concentration of solution before reaction at 0.15 mol/L, pH value at 7.5 and temperature at 75 oC.

Abstract: Pd composite membranes were prepared on macroporous α-Al₂O₃ tubes modified by silicalite-1 zeolite. Permeation tests of the Pd composite membranes were performed at 773 K to observe the H₂ permeance and H₂/N₂ selectivity. The H₂ flux and ideal selectivity for Pd composite membrane was 0.120 mol m⁻² s⁻¹ and 450 under 0.1 MPa, respectively. The variation of the membrane surface after elevating temperature in N₂ and air atmosphere was characterized in scanning electron microscopy (SEM) and energy dispersive X-ray spectrometer (EDS) analyses. As a result, it can be concluded that the formation of pinholes and defects on the membrane surface can be attributed to the oxidation of the Pd membrane.

Abstract: The microstructure, formability and corrosion resistance characters of industrially produced galvannealed coatings on high strength interstitial free (IF) steel with different galvannealing temperature have been investigated. With the galvannealing temperature increases, the Fe content of coating is increase, and the powdering resistance gets weaker while the corrosion resistance gets better. The coating microstructure consisting of a δ phase as the main constituent with a ζ layer on the top surface provides a good powdering resistance. The compact δ and Γ phases are good for the corrosion resistance of coating

Abstract: PAI/SiC-and PAI/SiC/PTFE-composite coatings were prepared, which were deposited on Al substrates using spraying technology to improve their surfaces performance. Friction and wear of PAI composite coatings were evaluated on a ball-on-block wear tester, and thermal properties were investigated by TG. It is found that, the friction coefficient and wear rate of PAI coatings reaches the best value when the content of SiC and PTFE is 10 wt % and 0.8wt% respectively, and the friction coefficient of the composites coatings decrease but the wear rate increase with increasing applied load; TG curves shows that the PAI composite coatings have excellent heat resistance. Furthermore, the surface of PAI coatings is perfect without bubbling, desquamating and cracking when it is heated for 2 hour at 250^◦C in turn three cycles.

Abstract: Electroless silver plating on the surface of fly ash cenospheres was prepared by slowly adding the solution of AgNO₃ into the mixed solution of D-glucose solution and alkaline solution after thermo-alkaline treatment. The morphology and composition of the silver-coated fly ash cenospheres composite powders were observed and analyzed by using SEM, EDS and XRD, and the influence of pH, loading quantity on silver plating was invested. The results revealed that, with the pH value of plating solution increasing, the precipitation of silver is improved, but led to self-accelerating decomposition if too high, and the influence of loading quantity on silver relative content and electro-conductivity of composite powders is very great. The silver shell of composite particles is even and compact when the pH value is 12.57 and the loading quantity is 4g/L, which resistivity can reach to 0.05Ω•cm.

Abstract: Removed due to plagiarism Original work is published Journal of Colloid and Interface Science 409 (2013) 227-236Dual-layered-coated mechanically-durable superomniphobic surfaces with anti-smudge properties Palanikkumaran Muthiah, Bharat Bhushan, Kyungsung Yun, Hirofumi Kondo www.elsevier.com/locate/jcis

Abstract: In recent years, the key research on thermal barrier coatings (TBCs) lies in the performance improvement of materials as well as structure and process improvement, and achieves new progresses. The difficulty is application of reliability in TBCs. Researchers are exploring that employing non-destructive testing (NDT) and life prediction model on TBCs to conduct a comprehensive and real-time detection and predict the life, so as to improve the safety of TBCs in service process.

Abstract: A numerical study using finite element analysis (FEA) was performed to investigate the thermal, shear and radial stresses developed in MAO coating on substrate of TC4 under thermal cycle loading. The four-node quadrilateral thermal solid element PLANE55 and four-node quadrilateral structural solid element PLANE42 with axisymmetric option was used to model the temperature distribution and thermal stress field of the MAO coating on TC4 substrates. The thermal stress, radial stress and shear stress along the thickness in film/substrate system are analyzed systematically under different thermal cycle loading. It is found that the thermal stress of MAO coating exhibits a linear relationship with thickness of substrate, but it exhibit a parabolic relationship with the thickness of the coating. The radial stress and shear stress distribution of the coating–substrate combination are also calculated. It is observed that high tensile shear stress of MAO coating on TC4 substrate reduces its adhesive strength but high-compressive shear stress improves its adhesive strength.

Abstract: The main aim of the authors research is to assess the investigation of durability T = f (v_c) in turning of the AISI 304 austenitic stainless steel with the CNMG 120408 coated carbide cutting insert. Experimental tests of selected material were realized in the CNC machine tool Doosan Puma 240 with Fanuc 21i TB control system. This experimental study is a continuation of the solutions of grant VEGA no. 1/9428/02 titled “The technological heredity of the machined surfaces - surface integrity”. The aim of the present paper is to focus scientific research on the impact of the various applied values of cutting speeds in the outer longitudinal turning. This paper, together with the achieved results is a basis that will optimize the performance of turning process of the austenitic stainless steel AISI 304 used for special applications with their dominant functional areas.