recent Advances in Sand Casting
-
Upload
9591007896 -
Category
Documents
-
view
32 -
download
1
description
Transcript of recent Advances in Sand Casting
-
5/27/2018 recent Advances in Sand Casting
1/25
Traditional Manufacturing Processes
Casting
Forming
Sheet metal processing
Cutting
Joining
Powder- and Ceramics Processing
Plastics processing
Surface treatment
-
5/27/2018 recent Advances in Sand Casting
2/25
Casting
Refractory moldpour liquid metalsolidify, removefinish
VERSATILE: complex geometry, internal cavities, hollow
sections
VERSATILE: small (~10 grams)very large parts (~1000 Kg)
ECONOMICAL: little wastage (extra metal is re-used)
ISOTROPIC: cast parts have same properties along all
directions
-
5/27/2018 recent Advances in Sand Casting
3/25
Different Casting Processes
Process Advantages Disadvantages Examples
Sand many metals, sizes, shapes, cheap poor finish & tolerance engine blocks,cylinder heads
Shell mold better accuracy, finish, higher
production rate
limited part size connecting rods, gear
housings
Expendable
pattern
Wide range of metals, sizes,
shapes
patterns have low
strength
cylinder heads, brake
components
Plaster mold complex shapes, good surface
finish
non-ferrous metals, low
production rate
prototypes of
mechanical parts
Ceramic mold complex shapes, high accuracy,
good finish
small sizes impellers, injection
mold tooling
Investment complex shapes, excellent finish small parts, expensive jewellery
Permanent
mold
good finish, low porosity, high
production rate
Costly mold, simpler
shapes only
gears, gear housings
Die Excellent dimensional accuracy,
high production rate
costly dies, small parts,
non-ferrous metals
gears, camera bodies,
car wheels
Centrifugal Large cylindrical parts, good
quality
Expensive, few shapes pipes, boilers,
flywheels
-
5/27/2018 recent Advances in Sand Casting
4/25
Sand Casting
-
5/27/2018 recent Advances in Sand Casting
5/25
History of metal casting Late 20th Century
Early 1970sThe Semi-Solid Metalworking (SSM)
process is conceived of at Massachusetts Institute of
Technology. It combines aspects of casting with aspects
of forging.
1971The Japanese develop V-Process molding. This
method uses unbonded sand and a vacuum. 1972The first production Austempered Ductile Iron
(ADI) component is produced by Wagner Castings
Company.
1976Compacted graphite iron (CGI), an iron withelongated graphite particles with rounded edges and
roughened surfaces, is developed in the U.K. It has
characteristics of both gray and ductile iron.
-
5/27/2018 recent Advances in Sand Casting
6/25
1982The Warm Box binder system was introduced.
1993First foundry application of a plasma ladle refiner
(melting and refining in one vessel) occurs at Maynard
Steel Casting Company in Milwaukee, WI. 1995Babcock and Wilcox, Barberton, OH, patent a lost
foam vacuum casting process to produce stainless steel
castings with low carbon content.
1996Cast metal matrix composites were first used in aproduction model automobile in the brake rotors for the
Lotus Elise.
1997Electromagnetic casting processes developed by
Argonne and Inland Steel Corporation. Electromagnetic
edge containment greatly reduces cost and energy
expenditures in steel production
-
5/27/2018 recent Advances in Sand Casting
7/25
Recent advances in sand casting technology
After 5000 years of technological advances, metal casting
plays a greater part in our everyday lives and is more essential
than it has ever been.
There are various developments in sand casting technology
which include advanced permanent molding, flexible machines
for metal mold casting, improved molding and solidification
practices for sand casting, rapid prototyping, Computer
modeling and simulation
Advanced casting processes are rapidly being adopted. These
include lost foam castings in volume production, continuous
castings, advanced semi permanent mold casting, semisolidcasting(SSM) and no bake Sand Castings
-
5/27/2018 recent Advances in Sand Casting
8/25
Lost foam casting
Lost foam casting(LFC) is a type of investment casting process
that usesfoam patternsas a mold. The method takes advantage
of the properties of foam to simply and inexpensively create
castings that would be difficult to achieve using other casting
techniques.
-
5/27/2018 recent Advances in Sand Casting
9/25
9
Variations and Developments
Continuous casting
Lost foam molding
3D Printing of Investment tooling
Direct printing with metal droplets
Uniform metal spray
-
5/27/2018 recent Advances in Sand Casting
10/25
10
Continuous casting ref AISI
Steel from the electric or basic oxygen furnace is tapped into a ladle and taken tothe continuous casting machine. The ladle is raised onto a turret that rotates the ladleinto the casting position above the tundish. Referring to Figure 2,liquid steel flows outof the ladle (1) into the tundish (2), and then into a water-cooled copper mold (3).Solidification begins in the mold, and continues through the First Zone (4) and Strand Guide (5).In this configuration, the strand is straightened (6), torch-cut (8), then discharged (12)for intermediate storage or hot charged for finished rolling.
-
5/27/2018 recent Advances in Sand Casting
11/25
11
3D Printing
of Investment cast tooling
-
5/27/2018 recent Advances in Sand Casting
12/25
12
Shell and part (Turbine blade)
-
5/27/2018 recent Advances in Sand Casting
13/25
13
Microcasting of droplets
CMUMIT
-
5/27/2018 recent Advances in Sand Casting
14/25
14
Environmental Issues
Smelting
Energy
Off-gassing see AFS webpage on green sand emissions;http://www.afsinc.org/environmental.html
Cooling water
Waste sand disposal
Off shore locations
-
5/27/2018 recent Advances in Sand Casting
15/25
15
Metal Smelting; reducing oxides and sulfides to
metal..
http://www.steel.org/learning/howmade/blast_furnace.htm
-
5/27/2018 recent Advances in Sand Casting
16/25
16
Environmental loads by
manufacturing sector
Carbon Dioxide and Toxic Materials per Value of Shipments
0
0.5
1
1.5
2
2.53
3.5
4
4.5
5
Chemicals
Petroleum
andC
oal
Plastics
and
Rubber
PrimaryM
etal
Fabricated
Met
al
Machinery
Electronic
Transportation
Manufacturing industries
Weight/Dollars
CO2 (metric ton/$10,000)
Toxic Mat'ls (lb/$1000)
EPA 2001, DOE 2001
-
5/27/2018 recent Advances in Sand Casting
17/25
Vacuum castingand molding
Similar to investment casting, except: fill mold by reverse gravity
Easier to make hollow casting: early pour out
3D Printing of Investment tooling:-
The Technology Used for
Creating 3D Printed Concept Models
1. Fused Deposition Modeling (FDM)
Technology
2. PolyJet 3D Printing Technology
-
5/27/2018 recent Advances in Sand Casting
18/25
No Bake Sand Casting No Bake is a casting process that uses chemical binders to bond the molding sand.
The sand is then transported to the mold fill station in preparation for filling of the
mold. A mixer is then used to blend sand with the chemical binder and the catalyst.
When the sand exits the mixer, the binder begins the hardening process.
After the compaction process, a rollover process is used to remove the mold from
the pattern box. The mould is then readied for handling the molten metal. After a
shakeout process, the molded sand is taken away from the casting. Then various
procedures follow including the finishing and the sand can be reclaimed by thermalmeans.
In the No-Bake resin sand casting process, sand molds are created using a wood,
metal, or plastic pattern. Sand is mixed with a plastic binder in a high-speed mixer.
This sand is deposited into box containing the pattern and all essential gating, risersand chills for pouring.
The sand mixture sets up hard in a few minutes and the mold is removed from the
pattern. Cores for forming internal passages in the castings are made using the same
process. Cores are carefully placed into the molds. The molds are then closed and
are ready for pouring.
-
5/27/2018 recent Advances in Sand Casting
19/25
Conclusion:As there is a growth in technology , there is an advancement in each and every
stage of casting process which proportionally reduces the cost and time of
manufacturing with an improved quality of a product.
References:-1. Degarmo, E. Paul; Black, J T.; Kohser, Ronald A. (2003), Materials and Processes in
Manufacturing (9th ed.), Wiley, ISBN 0-471-65653-4.
2. Todd, Robert H.; Allen, Dell K.; Alting, Leo (1994), Manufacturing Processes ReferenceGuide, Industrial Press Inc., ISBN 0-8311-3049-0.
3. Rao, T. V. (2003), Metal Casting: Principles and Practice, New Age International, ISBN
978-81-224-0843-0.
4. Campbell, John (2003), Casting (2nd ed.), Butterworth-Heinemann, ISBN 0-7506-4790-
66
-
5/27/2018 recent Advances in Sand Casting
20/25
TYPES OF MOLDING PROCESS
1 Expendable Mold
1.1 Permanent Pattern
1.1.1 Sand Casting
1.1.2 Plaster Molding
1.2 Expendable Pattern
1.2.1 Lost Foam1.2.2 Lost Wax
(investment casting)
1 Permanent Mold1.1 Die
1.1.1 Hot Chamber
1.1.2 Cold Chamber
1.1.3Thixotropic
Mold prepertation =) metal heating =) pouring =) cooling =) processing
-
5/27/2018 recent Advances in Sand Casting
21/25
Expandable mold
permanent pattern
SAND CASTING
-
5/27/2018 recent Advances in Sand Casting
22/25
SAND CASTING
-
5/27/2018 recent Advances in Sand Casting
23/25
The set of channels through which a moltenmetal flows to the mold cavity is called gating
system.
Typical gating system consists of a pouring
cupand a spruereceiving the poured melt,
runnera channel through which the melt is
supplied to the gates through which the
molten metal enters the mold cavity.
-
5/27/2018 recent Advances in Sand Casting
24/25
-
5/27/2018 recent Advances in Sand Casting
25/25