Glass/metal bonding

Bonding of flat surfaces Bonding of lighting housings Glass-metal bonding... 

Notes +150 C, intermittently, x (AI/AI, etched) substrate fiailure. Oily Steel 11 MPa Steel (clean/abraded) 16.5 MPa Oak 10 MPa (substrate fail). Gap filling 0.5mm. Notes Light transmittance >95%. a- glass/metal bond, x glass/glass bond. Gap filling 0.1mm. ... 

Torque strength of UV cured glass/metal bonds ... 

Phenolic-neoprene contact cements are used for structural metal-metal bonding. especially where fatigue resistance and low temperature performance are important [209]. They are also used for bonding textiles, wood, rubbers, plastics, ceramics, and glass to metal and to one another. Solvent toxicity and flammability has greatly reduced the use of contact cements in the wood products industry. Water-based contact cements persist, but generally do not perform as well as the solvent systems, thus allowing market erosion by alternative binders. 

Adhesive strength is evaluated at room temperature as well as at the extreme temperatures of —65°F and 180°F. Aircraft structure can reach —65°F at cruise altitudes and 180°F on the ground in a hot, sunny location. The types of toughened epoxies commonly used for metal bond adhesives have glass transition temperatures not much greater than 200°F, so properties fall off drastically at higher temperatures. 

Formulations (clear liquids or coloured formulations) based on an ethanol solution of various silica or aluminosilica precursors are marketed for application on glass, metallic or plastic surfaces to achieve hard 1 10 pm coatings that form strong chemical bonding with the surfaces and protect against staining or water corrosion. 

Metal-metal bonding, in molybdenum compounds, 17 29-31 Metal-modified glass-ionomer dental cements, 8 283... 

Finally, metal- and resin-bonded composites are also classified as particulate composites. Metal-bonded composites included structural parts, electrical contact materials, metal-cutting tools, and magnet materials and are formed by incorporating metallic or ceramic particulates such as WC, TiC, W, or Mo in metal matrixes through traditional powder metallurgical or casting techniques. Resin-bonded composites are composed of particulate fillers such as silica flour, wood flour, mica, or glass spheres in phenol-formaldehyde (Bakelite), epoxy, polyester, or thermoplastic matrixes. 

Reference was made earlier to difficulties of wetting plastics surfaces, and to problems in this regard compared with hydrophilic materials like glass, metals, and timber. With some plastics very effective bonds are possible, but as a group, mainly for this reason, they are amongst the most difficult to join by adhesives. 

Figure 9.5. A schematic representation of glass/metal interactions (a) a simple non-reactive oxide glass/metal interface across which only van der Waals interactions are developed (b) a more intense interaction between the metal and the oxide glass is developed by the presence of an adsorption layer with a typical thickness of 1 nm that is rich in oxygen (c) improved wetting and bonding produced by preoxidation or in situ oxidation of the metal that leads to the creation of a glass/MO interface.

In brittle materials, like glass, calculating the theoretical strength on the basis of breaking the bonds separating two layers in a material and forming two new surfaces makes sense in teams of the types of specific bonds in these systems. The metallic bond is non-specific, however, and failure of a theoretically perfect structure involves slip mechanisms along certain planes in the crys-... 

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