Casting Basics-> Sand Molds (A)

Question 1

What is CASTING?

Answer 1

Turning metal into a molten form and then pouring it into a cavity of the desired shape

Question 2

Advantages of CASTING

Answer 2

Create complex shapes(“organic”), and cavities and passageways

Question 3

Disadvantages of CASTING

Answer 3

Poor material properties causes large grain formation during cooling and defects. Hard dimensional control. Slow and energy intensive

Question 4

Expandable mold methods

Answer 4

The mold is destroyed and rebuilt every time it is used

Question 5

Permanent mold methods

Answer 5

The mold can be used multiple times

Question 6

What is “Charge material”?

Answer 6

The material that is initially fed into the process. (RAW MATERIAL, SCRAP METAL, PRE-ALLOYED METALURGICAL)

Question 7

FURNACES

Answer 7

Responsible for all molten metal production

Question 8

ELECTRIC-ARC

Answer 8

electric discharges

Question 9

INDUCTIVE

Answer 9

electricity induced by coils

Question 10

What is SLAG?

Answer 10

impurity that results when high temperature molten metal is exposed to atmospheric oxygen

Question 11

IRON ORE + COKE fuel make

Answer 11

Oxygen in the air react with the coke fuel, producing carbon monoxide

Question 12

SAND CASTING PROS

Answer 12

1. Readily Available and Cheap
2. Refractory properties
3. Reusable
4. Supports Heavy Loads
5. Conforms to Any Shape
6. Collapses for Part Shrinkage
7. Permeable to Steam and Gas

Question 13

Which sand is vastly used for SAND CASTING?

Answer 13

SILICA SAND (SiO2).
(abundant and inexpensive and high melting point)

Question 14

Three ingredients that BLEND for the perfect molding medium

Answer 14

CLAY, WATER and SAND

Question 15

What is BANK SAND?

Answer 15

20% CLAY, just add water, naturally occurring

Question 16

What is LAKE OR SHARP SAND?

Answer 16

processed sand, uniform pure silica sand

Question 17

What do CEREALS do?

Answer 17

added to help wick the water for a uniform moisture distribution

Question 18

What are MULLING MACHINES?

Answer 18

machines that mix sand, water, and clay

Question 19

What are alternative SANDS for SAND CASTING?

Answer 19

Zircon (ZrSiO4) (high thermal conductivity)
Chromite (FeCr2O4)
Olivine (MgFe)2SiO4

Question 20

What are PRE-TREATMENTS?

Answer 20

treatments done before the metal pour to improve performance

Question 21

What blend does the GREEN SAND MOLD use?

Answer 21

(most common)
SAND+CLAY+MOISTURE
green = moist

Question 22

What are the SKIN DRIED MOLDS?

Answer 22

Molds which have a heated surface layer of about 1/2 in. Improves surface finish.

Question 23

DRY SAND MOLDS

Answer 23

Baked in the oven after forming

Question 24

COLD CURE MOLDS

Answer 24

Uses a chemical binder rather than heat ton improve strength and surface finish

Question 25

What is a PATTERN?

Answer 25

3D representation of the final desired part.
Usually 3D PRINTED and made of plastic

Question 26

FLASK

Answer 26

the molding box. Top half is called COPE, bottom half is called DRAG. Held by LOCKING/LOCATING PINS

Question 27

Other components for SAND MOLD

Answer 27

TURNOVER BOARD and TAPERED DOWELS

Question 28

Parts of the FLASK

Answer 28

MOLD CAVITY, POURING BASIN, SPRUE, RUNNER, GATES, RISER, VENTS

Question 29

What is the purpose of the BLIND RISER?

Answer 29

To catch any SLAG(impurity) and slow down metal flow. Improves material properties/