Lec 9 Soldering (Intro) Flashcards
The joining of metal components by a filler metal, or solder, which is fused to each of the parts being joined.
Soldering
If the filler metal has a melting temperature greater than 450°C (840°F), the process is called ________.
Brazing
In ____________, the pieces that are joined are melted or fused together, without solder.
fusion welding
Solder can be used for joining, as in the fabrication of a fixed partial denture, or it can be used for building, as when an addition is made to the proximal surface of a crown.
Solder can be used for __________, as in the fabrication of a fixed partial denture, or it can be used for ___________, as when an addition is made to the proximal surface of a crown.
- joining
- building
____________ is the prime prerequisite of soldering, inasmuch as the soldering process depends on wetting of the surface to achieve bonding.
Cleanliness
____________ is the prime prerequisite of soldering, inasmuch as the soldering process depends on __________ of the surface to achieve bonding.
Cleanliness
wetting
______________, such as oxides and sulfides, that are present as a result of the casting process or that occur on the surface of metals when they are heated interfere with bonding.
Corrosion products
Placed on the surfaces to be soldered before they are heated. They may provide surface protection, reduce oxides, or dissolve oxides.
Flux
Soldering fluxes for noble metals are based on ___________.
They form low-fusing glasses that protect the metal surface, and they also reduce oxides such as copper oxide. They often are too fluid for preceramic soldering.
borate compounds
___________ are used on base metal alloys to dissolve the stable oxides of chromium, cobalt, and nickel. In addition to acting as solvents, these fluxes also serve a __________ role.
- Fluorides
- protective
Flux is more easily applied if it is in _______ form.
paste form
While a flux paste can be made with alcohol, the most popular form for use with noble metal alloys employs ___________ as a vehicle because it is more easily handled. It keeps air from the flux, and, when heated, the petrolatum burns off without leaving any residue.
petrolatum
Fluxes made from common borax, or pastes made with water, tend to effloresce when they are heated, producing pits in the solder joint.
Fluxes made from ________, or pastes made with water, tend to effloresce when they are heated, producing pits in the solder joint.
common borax
common borax
Fluxes made from ________, or pastes made with water, tend to effloresce when they are heated, producing pits in the solder joint.
petrolatum
Fluxes made from ________, or pastes made with ________, tend to effloresce when they are heated, producing pits in the solder joint.
common borax
water
A material used to outline the area to be soldered in order to restrict the flow of solder.
Antiflux
The most common antiflux is the mark of a ___________, which works best on surfaces that do not have a high polish.
soft graphite pencil
Gold solders are classified by ________ and by _______.
fineness
carat
refers to parts per thousand of the solder that is gold.
refers to parts per thousand of the solder that is gold.
fineness
Refers to parts per thousand of the solder that is gold.
fineness
Refers to parts per 24 of a metal that are gold.
carat
The actual noble metal content of the solder would be given by its __________ rather than by its carat.
fineness
The higher the __________ of a solder, the higher will be its ________ and the greater its ____________.
fineness
melting range
corrosion resistance
flow
While a solder with a lower fineness has a lower melting range, it also has poorer ________ characteristics.
While a solder with a lower fineness has a lower melting range, it also has poorer ________ characteristics.
Refers to parts per thousand of the solder that is gold.
fineness
____________ (iron oxide) suspended in chloroform can also be painted around the area of the solder joint to prevent undesired spread of the solder.
Polishing rouge
The higher the __________ of a solder, the higher will be its ________ and the greater its ____________.
fineness
melting range
corrosion resistance
While a solder with a lower fineness has a lower melting range, it also has poorer ________ characteristics.
poorer flow
The minimum fineness that should be used is _____ fine, and a higher number would be better for preventing tarnish and discoloration.
580
The solder should possess a fusion temperature that is about ____________ below that of the metal being soldered.
60°C (100 to 150°F)
________ in solder is not desirable. More of it that occurs when there is an increased amount of ________ in the solder, which may vaporize when the gap between the components is too narrow or when the solder is over- heated.
Pitting
base metal
Solder should be as strong as the alloy with which it is used. The hardness of the solder decreases as the_________ increases.
fineness (gold content)
The solder should flow freely.
- _________ in the solder tends to make it adhere to metal and to flow more freely.
- __________ makes it more sluggish.
Solders that melt at _________ temperatures have a lower surface tension and flow easily through narrow gaps.
______- fusing solders flow poorly through narrow gaps.
- Silver
- Copper
- higher
- Low
____________ (iron oxide) suspended in chloroform can also be painted around the area of the solder joint to prevent undesired spread of the solder.
Polishing rouge
Refers to parts per thousand of the solder that is gold.
fineness
