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Use of Conventional Manufacturing Techniques for Materials
Published in T. S. Srivatsan, T. S. Sudarshan, K. Manigandan, Manufacturing Techniques for Materials, 2018
T. S. Srivatsan, K. Manigandan, T. S. Sudarshan
This technique has been used for the joining of materials by means of an adhesive. Adhesion is facilitated due to molecular attraction between the adhesive and the workpiece. Since both metal and nonmetals can be bonded, adhesive bonding has grown significantly with the emergence of plastic and composite materials. After cleaning of the surfaces, the adhesive is applied between the faying surfaces by chemical or mechanical means. The strength of the joint is strongly governed by the absence of dirt, dust oil, and other contaminants. The presence of contaminants on the surfaces to be joined impairs the wetting ability of the adhesive and prevents its spreading evenly over the interface (Pizzi and Mittal 2003).
General introduction
Published in Adedeji B. Badiru, Handbook of Industrial and Systems Engineering, 2013
Joining processes (Figures 19.13-19.15) are employed in the manufacture of multipiece parts and assemblies. Joining processes include mechanical fastening (bolting and riveting), adhesive bonding, and welding processes. Welding processes use different sources of heat to cause localized melting of the metal to be joined or the melting of a filler to develop a joint between two metallic parts. Clean faying surfaces are joined together through a butt weld or a lap weld, although other configurations are also possible. Two other joining processes are brazing and soldering, which differ from each other in the temperature applied.
The Design of Joints Loaded in Shear
Published in John H. Bickford, An Introduction to the Design and Bchavior of Bolted Joints, 2018
In general, faying surfaces should be clean and dry at assembly. Loose scale, dirt, etc., should be removed by wire brushing, but clean mill scale should not be removed unless the joint is going to be grit-blasted, or the equivalent, to roughen the surfaces (which should never be polished or buffed or “smoothed”).
Investigating the transient liquid phase bonding (TLPB) behaviour of a Palladium containing Ni-B based braze filler metal
Published in Canadian Metallurgical Quarterly, 2020
Inconel 625 (IN625; Ni-21Cr-9Mo-4Fe-3.7Nb) base metal cylinders were provided by Pratt and Whitney Canada (P&WC) with a dimension of 4.5 mm diameter × 3 mm in height. TLPB was simulated within the DSC using a half joint arrangement depicted in Figure 1, where cylinders of IN625 were placed in contact with a powder bed of CPW475 (Ni-36Pd-10.5Cr-3B-1Si wt%) braze alloy. The weight of the powder bed used was in the range of 7.03 mg ±1%. Upon melting, this weight of powder resulted in a uniform filler thickness of 39.9 µm ±3.5% spread across the base metal faying surface. The weight of the base metal cylinders was in the range of 296 mg ±4%. To limit the area of interaction of the braze material to the bottom of the surface facing down (i.e. the faying surface), the sides and top of the cylinders were painted with yttria. The flat faying surface was polished using a 500 grit SiC paper and ultrasonically cleaned in acetone to create a clean, unoxidised surface to allow wetting by the molten braze filler. This surface preparation method is an accepted commercial practice and commonly used by TLPB researchers [1–7].
Finite element modelling of the stress-strain state in specimens from dissimilar Ni-based alloys during pressure welding with displacement
Published in Welding International, 2019
A. Kh. Akhunova, S. V. Dmitriev, V. A. Valitov, E. V. Galieva
Thus, we may draw the following conclusions: In PW, effected with a combination of inserting and rotating the shaft, the values of the coefficient of friction k and of the angle of taper of the shaft α exert a significant influence on the magnitude of the compressive stresses σR. However, in PW only with insertion of the shaft, the influence of k can be ignored, if the value of α does not exceed 2°, since at higher taper angles there is a sharp increase in σR and undesirable plastic deformation of the upper part of the shaft.To create a permanent joint of the disk and shaft it is preferable to use PW, carried out with a combination of inserting and rotating the shaft. This provides a two-component shear strain εRZ and εRθ, stimulating relative shear of the faying surfaces, which improves the quality of the welded joint.To increase the quality of the welded joint between shaft and disk, shaft taper is necessary for all the schemes of PW examined. The value for an efficient angle of shaft taper is recommended to be within the range 0 < α ≤ 2°. With said value of α, no marked deformation of the shaft and disk occurs, since the plastic strains are very small, but the maximum shear strains increase, and they become more uniformly distributed in the zone of the contact surfaces. Then, in the case of PW carried out with a combination of inserting and rotating the shaft, special attention must be paid to treatment of the faying surfaces, because if there is a high level of friction, there is a danger of subjecting the shaft to large plastic strains.