Soldering Richard Whitehouse（焊接理查德·怀特豪斯）.pdfVIP

Silver Soldering A matter of terminology The process of joining metal parts through the use of heat and a filler metal is commonly called “soldering” by manufacturing jewellers and silversmiths. Actually, this term is incorrect by today’s definitions. The joining of metals in th e temperature range of 593° C to 871° C is properly called brazing. (The term “soldering” is used to describe metal-joining operations at temper atures below 427° C. However, the term “soldering” is so firmly established in the industry that we will use it in the discussion that follows, rather than the more technically exact term “brazing:” No harm will be done, as long as it is understood that when we talk about soldering we are talking about metal joining operations in the range 59 3° to 871° C. General outline Soldering is the joining together of two or more parts of the same metal through the fusion of heated alloys called solders which melt at a lower temperature than the melting point of the metal being joined. The solder alloy melts, but there is no melting of the metals or alloys being joined. The solder flows between these parts, drawn by capillary attraction. The base metal is not fused, but the solder diffuses into the base metal, it makes a surface alloy with the base. A soldered joint in a sense “makes itself” Capillary action does the work, drawing the molten solder completely through the joint. But even a properly designed soldered joint can turn out imperfectly unless the correct soldering procedures are followed. These procedures can be boiled down to six basic steps. They’re generally simple to perform (some take only a few seconds), but every one of them is essential to the completion of a strong, clean soldered joint. Soldering Technique Silver soldering cannot be accomplished without using flux. The joining surfaces are first cleaned mechanically and then coated with a flux, usually of borax or soldering powders such as Easy Flo or Tenacity No.5