Bonding processes

Evaluation of Bonding Process in Diffusion Bonding Joints of Dissimilar Metals using Ultrasonic Testing Method. 

This study was in real time measured that the reflective echo height of the bonding interface in the solid phase diffused bonding process of carbon steel and titanium using ultrasonic testing method. As a result, the following were made discernment. 

The plastic deformation, the creep deformation, and the bonding process on the bonding interface can be presumed from the height of the echo. 

On the other hand, the reliability of the product improves, too, if each state of the plasticity deformation, the creep deformation, and the diffusion joint in the solid phase diffusion bonding as the bonding process, is accurately understood, and the bonding process is controlled properly. 

Uses and Treatments of Hardwood Plywood. Most early appHcations of hardwood plywood were those where the hardwood plywood was better adapted to the use than soHd wood. One of the most important early uses was in curved or formed parts, an appHcation particularly suited to the use of veneers which could be molded into intricate shapes during the pressing and bonding process. Then, as furniture manufacturers realized the inherently superior stabiHty of plywood compared to soHd wood, lumber-core or plywood panels began to be used for most flat-panel constmctions in furniture. 

The explosive cladding process provides several advantages over other metal-bonding processes ... 

When the explosion-bonding process distorts the composite so that its flatness does not meet standard flatness specifications, it is reflattened on a press or roUer leveler (ASME SA20). However, press-flattened plates sometimes contain localized irregularities which do not exceed the specified limits but which, generally, do not occur in roU-flattened products. 

Fig. 4. Diffusion bonding process (a) apply metal foil and cut to shape, (b) lay up desired pHes, (c) vacuum encapsulate and heat to fabrication temperature, (d) apply pressure and hold for consoHdation cycle, and (e) cool, remove, and clean part.

Fig. 5. Roh bonding process of making a laminated MMC a metahurgical bond is produced.

Nonwoven bonding processes iatedock webs or layers of fibers, filaments, or yams by mechanical, chemical, or thermal means. The extent of bonding is a significant factor ia determining fabric strength, dexibiUty, porosity, density, loft, and thickness. Bonding is normally a sequential operation performed ia tandem with web formation, but it is also carried out as a separate and distinct operation. 

Smooth surfaces are normally estabflshed by calendering, a process which subjects the fabric at the nip point(s) of two or more roUs to the influence of controlled time, temperature, and pressure. When calendering is used as a thermal-bonding process, the roUs are of the same dimension and composition and are independently driven. However, when calendering is used as a fabric finishing operation, the roUs are frequently of different dimensions and composition and are not always independently driven. 

Paraffin wax additives are effective in overcoming surface inhibition by forming a monomolecular wax layer at the curing surface. Although effective in excluding oxygen, this waxy layer must be removed for subsequent lamination or bonding processes (see Waxes). 

Nonmetal haUdes are generally hydroly2ed to a hydrogen haUde and to an oxy-acid containing the other element. The first row nonmetal haUdes, eg, CCI4, resist hydrolysis because the nonmetal element cannot expand its octet of electrons to form a bond to water before its bond to the haUde is broken. Hydrolysis requires either an energetic water molecule to strike the haUde or ioni2ation of the covalent nonmetal—halide bond, processes that tend to be quite slow (16). 

Some of the restrictions on the use of aluminum are caused by manufacturing and fabrication problems and by its low mechanical strength. However, aluminum is widely used and is competitive with Type 316 stainless steel in many instances. The explosion-bonding process has made the aluminum cladding of steel practical, and... 

The solvent-borne NR adhesives show an important mechanical component in the bonding process, and therefore bulk mechanical and rheological properties (addition of fillers is quite effective) are important. In fact, these adhesives are mainly suitable when at least one of the surfaces to be joined is water-porous (paper, concrete, leather, textiles). 

Application equipment. Laboratory or pilot scale equipment that closely simulates the actual bonding process under production conditions. For some applications this is simple table top equipment, while for others this may be an expensive pilot line with a skilled operator. 

Fig. 5. Viscosity versus time — bonding process for a waterborne polyurethane dispersion.

Bishopp, J.A., A brief history of the redux bonding process, structural adhesives in engineering V, 5th Int. Structural Adhesives in Engineering Conference (SAE-V). Bristol, UK, 1998. 

Influence of the adhesive on the bonding process and the properties of wood products... 

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