WELD STRENGTH

Ultrasonic Welding. Ultrasonic welding has been appHed to Tefzel with weld strength up to 80% of the strength of the base resin. Typical conditions include a contact pressure of 172 kPa (25 psi) and 1—2 s cycle time. The two basic designs, the shear and butt joints, employ a small initial contact area to concentrate and direct the high frequency vibrational energy. 

Welded Tube Joints When suitable materials of construc tion are used, the tube ends may be welded to the tube sheets. Welded Joints may be seal-welded Tor additional tightness beyond that of tube rolling or may be strength-welded. Strength-welded Joints have been found satisfactoiw in veiy severe seivdces. Welded Joints may or may not be rolled before or after welding. 

Once a process is being used, recognize that if the compound additives or fillers are changed or added, bond performance can change or even not exist. As an example an unreinforced plastic can be welded to itself however with a certain amount of glass fiber fillers (they do not melt) added to the plastic, action in weld strength can be reduced or even eliminated. 

Material Percent of Weld Strength Spot Weld Staking and Inserting Swaging Weldini Near Field F ... 

Weld strengths are based on destructive testing. 100 + % results indicate that parent material of plastic part g. way while weld remained intact. 

LCPs are handicapped by a high anisotropy of properties, shrinkage and thermal expansion low weld strength the cost, though justified by the performances and unusual design rules. 

In plastics applications, wollastonite reinforces, increases scratch resistance, improves thermal stability, increases welding strength, and decreases warpage and... 

Figure 7.12 Schematic diagram of a microtensile bar for weld strength measurement.

Weld Factor - The ratio of weld strength to the strength outside the welded zone, t5q)ically determined by tensile stress tests. 

Weld Strength - Strength of a welded plastic part at the seam that has been welded is called weld strength. It is measured by methods similar to those for measuring the strength of adhesive bonds. See dl ,o Adhesive Bond Strength. 

ULDPE/CSR or CPE, dynamically vulcanized, then dispersed into fresh CSR or CPE processability, hot-weld strength, adhesion and crack resistance for single-ply roofing membranes Ainsworth, 1990, 1994... 

Aluminum alloy 6013 is a relatively new heat treatable alloy of medium strength that derives its heat treat response from the precipitation of magnesium-silicon and an Mg-Si-Cu-Al phase. Alloy 6013 is weldable by GTA, MGA, and resistance methods. It has similar weldability to 6061 when welded by arc methods using 4043 or 4063 hllers and has weld strengths typically 27 to 40 MPa (3.9 to 18 ksi) higher than 6061. 

Weld strength In many applications, optimization of weld strength may not be required. This allows more freedom on weld parameters. As such, lower strengths may be acceptable. This, for example, can allow for higher rotation speeds, which lower force requirements. 

There is no alternative, that is, where the welding is an enabling technology, and no other joining process can compete with the weld strength provided by FSW. 

Fig. 12.25 (a) Failure loads for friction stir spot welded 5052. (a) 1 mm (0.04 in.) single overlap, (b) 1 mm (0.04 in.) double overlap, (c) 1.6 mm (0.06 in.) singleoverlap configuration. Mechanical properties are not significantly influenced by plunge depth with increasing tool rotation rate. The thicker sheet exhibits lower weld strength. Source Ref 21... 

Fig. 13.17 Ungu ided lap shear strength (pounds per inch of friction stir weld) for aluminum alloys compared to industry specification values for minimum spot weld strength and rivet shear strengths...

Figure 2.38. Weld strength vs. tool temperature (time = min). [Data from Stokes, V. K., J. Vinyl Additive Technol, 6, 3, 158-165,2000.]...

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