Papers by Keyword: Interfacial Bonding Strength

Abstract: For the characteristic that the mechanical properties of resin composite are lower than cast iron, steel fibers are used to improve its properties in this paper. A weak interfacial bonding strength between steel fibers and resin indicates that steel fibers’ property cannot perform well in the polymer. In order to improve the interfacial bonding strength, four methods of surface treatment, phosphating, acid pickling, oxidation, and coupling are applied to steel fibers, and the corresponding pull-off tests are carried out to compare with untreated steel fibers. Research results show that the maximum interfacial bonding strength is increased by 45.1% after coupling treatment.

Abstract: ¹̄The Ni-P-W/Al₂O₃ composite coatings were deposited on the NdFeB magnetic materials surface by electroless plating method. The morphology of Ni-P-W/Al₂O₃ coatings was investigated using scanning electron microscopy. And the X-ray diffraction was used to identify the phase constituents. The interfacial bonding strength between Ni-P-W/Al₂O₃ composite coatings and NdFeB matrix was also tested. The results indicated that the interfacial bonding strength is prone to be increased while the Al₂O₃ powders co-deposited with Ni-P-W coatings. And the interfacial bonding strength would reach the highest value when the Al₂O₃ concentration is in rang of 5gL^-1 to 10gL^-1.

Abstract: Strengthening and toughening efficiency contributed by calcium carbonate whisker was questioned in this study when the interfacial bonding strength between whisker and Portland cement was increased by adding silica fume. A simple proving experiment was employed and the basic mechanical properties were measured. The results showed that the compressive strength of the composites with silica fume was more sensitive to whisker loading. The flexural strength, split tensile strength and work of fracture were increased no matter with or without silica fume. However, the strengthening and toughening efficiency caused by whiskers in the composites with silica fume was lower than that without silica fume. The scanning electron microscopy images illustrated six mechanisms which can account for the strengthening and toughening effects. It is concluded that crack deflection was the efficient mechanism to toughen cement composite materials. And the interfacial bonding strength should be weak enough to introduce more crack deflection mechanism.

Abstract: Laminated glass and photovoltaic laminated glass are widely used in architecture. The interfacial bonding strengths between poly(vinyl butyral) (PVB) and glass were investigated by the cross-bonding method from room temperature to -50 °C. The loading speed was 5 mm/min, and the cooling speed was about 0.5 °C/min. The testing sample was hold at each temperature for half an hour. It was revealed that the testing temperature had great effect on the bonding strength. At room temperature, the tensile bonding strength was 11.49 MPa and the shear bonding strength was 6.61 MPa. With the temperature decreased from RT to -50 °C, the tensile bonding strength was decreased by 66.81%, but the shear bonding strength was increased by 212.16%. From RT to -30 °C, the change rates of the tensile and shear bonding strength bonding strength were 65.57% and 172.68% respectively, only 3.61% and 14.48% from -30 °C to -50 °C. The mechanism for the bonding strength depended on testing temperatures from RT to -50 °C was also discussed.

Abstract: This study presents impact properties and interfacial strength of Ultra-high molecular weight polyethylene fiber plain woven fabric reinforced vinyl ester composites with different matrix volume fraction. The interfacial strength was found to be decreased by reducing the matrix volume fraction. Stress, strain and energy absorption per thickness in the impact process were evaluated and the relation between these impact parameters and interfacial strength of the laminates were investigated. The maximum stress was decreased and the maximum strain was increased with the drop of interfacial bonding strength. The experiment results also revealed that the sample with a matrix volume fraction 23% showed higher energy absorption than other ones.

Abstract: Ultra-high molecular weight polyethylene fiber plain woven fabric reinforced line-low-density polyethylene composites with different matrix volume fraction were prepared. The interfacial bonding strength and the impact property of the laminates were investigated. The experiment results revealed that the sample with a matrix volume fraction 14% showed better impact properties than other ones, while the interface bonding strength continued to drop when the matrix volume fraction was decreased. It is also indicated that in high fiber interface bonding strength, the impact resistance of the laminate would grow by decreasing the interface bonding strength. However, when the interface bonding strength was lower than the threshold, there would be an opposite effect.

Abstract: This study was conducted to evaluate the groutability and interfacial bond strength of polymer modified cement grouts (PMCG) for repair and rehabilitation of concrete pavement with different polymer/cement ratio. The groutability of grouts was studied through the cone-shaped gap test and the grouted minimum gap width was determined. The interfacial bond strength, such as flexural and shear bond strength were measured. The experimental results indicate that the groutability of grouts modified by vinyl acetate/ethylene copolymer (EVA) improves obviously and the grouted minimum gap width decreases. The flexural and shear bond strength increase 32.41% and 122.92% when the polymer/cement ratio is 10%, at the ages of 28 days respectively. The microstructure of repair interface was observed and analyzed by using scanning electron microscope, and the modification mechanism of EVA latex was discussed.

Abstract: Reactive magnetron sputtering technique was used to gain titanium nitride (TiN) films on W18Cr4V high-speed steel and GCr15 bearing steel substrates at low temperature. The Surface chemical composition of the films was analyzed using energy dispersive X-ray spectroscopy (EDXS) and the surface morphology was examined using atomic force microscopy (AFM). Moreover, a series of experiments have been conducted to study the relationship between interfacial bonding strength and some major technological parameters, that is, substrate surface roughness, negative bias voltage, intermediate transition layer, substrate hardness, and ion etching before deposition. The experimental results have indicated that the TiN film with typical ratio of chemical metric can be deposited on substrates using reactive magnetron sputtering technique below 140°C. The AFM image has showed that the TiN film using magnetron sputtering technique was composed of densely distributed nano-grains with uniform structure. Its surface was flat and smooth. The indentation testing results have showed that the increase of surface roughness and substrate hardness improves the bonding strength of TiN / substrate significantly. Furthermore, the bonding strength of TiN / substrate can also be improved through the following methods: (1) choosing a proper intermediate transition layer; (2) adopting ion etching before deposition and (3) increasing negative bias voltage before deposition.