Е. С. Закирова, П. А. Красавин Английский язык для технических вузов



Pdf көрінісі
бет150/267
Дата06.09.2022
өлшемі4,38 Mb.
#148861
түріУчебник
1   ...   146   147   148   149   150   151   152   153   ...   267
Байланысты:
doc7608079 607043726

JOINING PROCESSES
A mechanical joint is a part of a machine which is used to connect another 
mechanical part or mechanism. Mechanical joints may be temporary (with the 
help of bolts, screws, studs, etc.) or permanent (welding, brazing, soldering, 
and riveting).
Bolted joints are considered to be temporary mechanical joints and may 
be disassembled when required. They consist of fasteners that capture and join 
other parts, and are secured with the help of screw threads. 
Welding is a fabrication process that joins materials, usually metals or ther-
moplastics, by causing coalescence. This is often done by melting the work 
pieces and adding a filler material to form a pool of molten material that cools 
to become a strong joint, but sometimes pressure is used together with heat, 
or by itself, to produce the weld.
Brazing is a joining process in which a filler metal is melted and drawn into 
a capillary formed by the assembly of two or more workpieces. The filler metal 
reacts with the workpiece(s) and solidifies in the capillary, forming a strong 
joint. Unlike welding, the workpiece is not melted. Brazing is similar to solder-
ing, but occurs at temperatures in excess of 450 °C (842 °F).
Soldering is a joining process that occurs at temperatures below 450°C 
(842 °F). It is similar to brazing in the fact that filler is melted and drawn into 


173
a capillary to form a join, although at a lower temperature. Because of this 
lower temperature and different alloys used as fillers, the metallurgical reaction 
between filler and workpiece is minimal, resulting in a weaker joint.
Riveting is one of the most ancient metalwork joining processes. Its use 
has declined markedly during the second half of the 20th century, but it still re-
tains important in the 21st century. The earlier use of rivets is being superseded 
by improvements in welding and component fabrication techniques.
Bolted joint 
Screw joint 
Stud joint


Достарыңызбен бөлісу:
1   ...   146   147   148   149   150   151   152   153   ...   267




©engime.org 2024
әкімшілігінің қараңыз

    Басты бет