What is a sand slinger?
feeds the sand to the molding board and molding line
Chaplets
internal cavities or passages
Hot Spots
Isolated pools of liquid form inside solidified metal
Fillets and Rounds
radial edge features
Draft
taper or slope given to cores or other parts
Shrink
Metal shrinks as it transforms from liquid to solid
sprue
the entry point and vertical passage for molten plastic material
riser
a reservoir built into a metal casting mold to prevent cavities due to shrinkage
runner
channels in a mold through which molten metal is poured to fill the mold cavity
cavity
the portion of a cast which forms the external shape
pouring basin
funnel-shaped inlet, situated atop the system
Precision/Investment Casting
wax to make the mold and then replaced with metal to create complex and intricate parts
what the precision of the instruments is
Degree of repeatability of the instrument
How does temperature affect measuring instruments?
Temperature control is very important to maintain high accuracy. 20ºC±0.3ºC(68ºF±0.5ºF) is the standard measuring temperature
Drilling for taps
drill a smaller hole than the tap
Starting Drills
make sure drill is not touching piece
Drill and boring round holes
drill a smaller hole then bore it to the correct size
Continuous Chips
not ideal can cause defects. to stop increased rotation or slow-cutting speed
Welding rod designations
1st = Electrode 2nd= Min. tensile (in KSI) 3rd=position, 4th=type of current and coating
Brazing (Bronze Welding)
process of joining two pieces of bronze using a third metal alloy with a lower melting point than the base metals
MIG
wire fed
TIG
rod fed
Where would you use submerged arc welding?
Limited to flat and horizontal welding. Used in big projects like ship building.
Can you weld aluminum to steel [other than with friction welding]?
yes, explosive welding
DCEN (Straight Polarity)
good for fillet welding in the flat position, flats, and vertical up welding
DCEP (Reverse Polarity)
The metal flow is from the work-piece to the electrode
Stick saftey
protective wear
Oxyacetylene Welding Saftey
acetylene must be below 15 psi
What DC stick welding process do we use for overhead welding?
DCEP-reversed
What DC stick process do we use for horizontal – flat welding?
DCEN
Flash Welding – How they make bandsaw blades
Uses heat and pressure as this is another type of resistance welding
Resistance Seam Welding
like overlapping spot welding
Inertial Welding
friction welding
Welding Dissimilar Metals
combining different types of metals
Welding Thin Metal
typically done with mig
electron beam welding
AUTOGENOUS in that it used the base metal to create the weld
Types of rolling
cold, hot
Cambering, spreading
roll a piece flat by rolling with round rollers
Rolling defects
Wavy edges – roll bending
Cracks – low material ductility at the rolling temperature
Types of forging
cold, hot
Grain alignment
smashed together
Sheet-metal forming
process is performed on a press using a set of tools called die and punch
broaching
tool removes material from a workpiece in a consistent, continuous, and accurate way
TiN [titanium nitride]
It is used as wear protection in cutting tools
Define a properly knurled part
sharp diamond points
Surface Plate
the main horizontal reference plane for precision inspection, marking out (layout), and tooling setup
Angle plate
plate that is set to an angle that is used as a reference
Micrometer Use
precision measuring tools used to measure very small objects
Burning
utilizes a high temperature for removing material
Types of Grinding
Surface, Center, Center-less,
Mohs Scale
Used to determine hardness
Grit Sizes
based on screen mesh size
Precision
highly precise and efficient manufacturing process
Snag Grinding
Rough grind
What abrasive is the hardest?
Synthetic Diamonds