60807
Description
Flashcards by Brandon Alcaraz, updated more than 1 year ago
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Created by Brandon Alcaraz
over 11 years ago
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| Question | Answer |
| How do brazing and soldering differ from the solid-state welding processes? | In brazing and soldering, a filler metal is added, whereas in solid state welding no filler metal is added. |
| What is the technical difference between brazing and soldering? | In brazing the filler metal melts at a temperature above 450C (840F). In soldering the filler metal melts at a temperature of 450C or below. |
| Under what circumstances would brazing or soldering be preferred over welding? | Brazing or soldering might be preferred over welding if (1) the base metals have poor weldability, (2) the components cannot tolerate the higher heat and temperatures of welding, (3) production rates need to be faster and less expensive than welding, (4) joint areas are inaccessible for welding but brazing or soldering is possible, and (5) the high strength of a welded joint is not a requirement. |
| What are the two joint types most commonly used in brazing? | The two joint types most commonly used in brazing are butt and lap joints. 31.6 |
| Certain changes in joint configuration are usually made to improve the strength of brazed joints. What are some of these changes? | In butt joints, the butting surface areas are increased in various ways such as scarfing or stepping the edges. In brazed or soldered lap joints, the overlap area is made as large as possible. Several of the adaptations are illustrated in the figures of this chapter. |
| The molten filler metal in brazing is distributed throughout the joint by capillary action. What is capillary action? | Capillary action is the physical tendency of a liquid to be drawn into a small diameter tube or other narrow openings in spite of the force of gravity. It is caused by the adhesive attraction between the liquid molecules and the solid surfaces that define the narrow openings. |
| What are the desirable characteristics of a brazing flux? | The desirable characteristics of a brazing flux are (1) low melting temperature, (2) low viscosity when melted, (3) promotes wetting of metal surfaces, and (4) protects the joint until solidification occurs. |
| Best clearances between surfaces in brazing are which one of the following: (a) 0.0025-0.025 mm (0.0001-0.001 in.), (b) 0.025-0.250 mm (0.001-0.010 in.), (c) 0.250-2.50 mm (0.010-0.100 in.), or (d) 2.5-5.0 mm (0.10-0.20 in.)? | b |
| Which of the following is an advantage of brazing (three best answers): (a) annealing of the base parts is a by-product of the process, (b) dissimilar metals can be joined, (c) less heat and energy required than fusion welding, (d) metallurgical improvements in the base metals, (e) multiple joints can be brazed simultaneously, (f) parts can be readily disassembled, and (g) stronger joint than welding? | b, c and e |
| How do brazing and soldering differ from the fusion-welding processes? | In brazing and soldering, no melting of the base metal(s) occurs. |
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