Thermal Distortion Testing - afsinc.s3.amazonaws.com Sand Casting Conference October 20-22, 2014...
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AFS Sand Casting Conference October 20-22, 2014 – Indianapolis, IN USA Thermal Distortion Testing Sam Ramrattan Department of Engineering Design, Manufacturing and Management Systems Western Michigan University
Transcript of Thermal Distortion Testing - afsinc.s3.amazonaws.com Sand Casting Conference October 20-22, 2014...
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Thermal Distortion Testing
Sam RamrattanDepartment of Engineering Design, Manufacturing and Management Systems
Western Michigan University
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
The expansion, contraction, and degradation experienced by a
mold/core under extreme heat and liquid pressure of the molten metal
Thermal Distortion Testing (TDT)
Effects:•Expansion oversized castings
•Distortion penetration, veins / rat tails
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Rat Tail Penetration
Consequence of Problems
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
TDT - Stresses on Specimen
TDT Measurements
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
TDT
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Effect of Compression and Tension
Forces on a Sand Disc Specimen
Before
TDT
After TDT (White
unbounded
sand)
After TDT (Tensile crack
present after
10psi blow)
After TDT(Back Side)
Hairline
Crack
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Samples Before
Elevated to
Temperature
After TDT (Blown with 10psi)
As-CastCompression
Surface
As-CastTension
Surface
SHL
PUCB
FUR
AIO
Vein
Penetration
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
TDT Curves
Reminder: Percent binder and sand type held constant
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Old Disc Concerns
Non-uniform specimen density
Density histogram and XRCT image
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Old Disc Specimens
Uncoated DiscDisc refractory coated
at 34% solids
Raised Parting Line
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Old Disc Tooling
Three-cavity core box
• Vertically parted
• Two vents per cavity
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
New Disc Tooling
• Three piece tool to avoid raised parting line on test surfaces
- Inserts can be of different thicknesses
• Distributed venting to reduce density variation
• Layout with radial symmetry to reduce cavity to cavity specimen variation
• Simple shape allows for easier addition to tooling
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
New Disc Tooling
Three-piece tooling for new disc specimens
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
New Disc Tooling - Insert
• Radial symmetry
• Flat faces on testing features
• Parting line venting applied to disc perimeter
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
New Disc Tooling Specimens
“Tree” of disc specimens produced in new tool
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Simulation
Core Blowing – Volume Fraction
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Simulation
Predicted Specimen Density
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Simulation
Core Blowing – Air Velocity Vectors
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Simulation
Core Curing – Curing Front Progression
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Testing parameters:
Old vs New tooling specimens
• Same test conditions
• Control of specimen recipe
- Same sand
- WI, 65 AFS/gfn, Round
• Same binder system
• Same binder level
- 0.9%
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Results
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Results
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Results
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Results
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Results
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Identifying time till crack occurrence
-0.02
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
-10 10 30 50 70 90
Dis
pla
cem
en
t
Time
Raidial movement
10--1
10--2
10--3
10--4
10--5
10--6
10--7
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Map & Measure the HAZ
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Image Analysis
Sample - Before Test
Sample - After Elevated
Temperature Exposure Displacement Composite Overlay
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Measurement of As-Cast Defects
Note: Neutral Surface Determined from Pretested Specimen Surface
SHL Vein:
Max Height 0.02in
PUCB Penetration:
Max Height 0.061in
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
CastExpo ‘10March 20-23, 2010
Orlando, FL USA
Coating Properties Measurement
Coating % Solids
Surface Tension
[7.5 sec to
equilibration]
(Dyne/cm)
Ct1 (0.35%
Surfactant)
38% 26.60
±0.01 ± 0.24
Ct3 (0.15%
Surfactant)
38% 30.39
±0.01 ± 0.77
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Differences in Sand Distribution
710 430
before TDT after TDT(coated side)
after TDT(back side)
Resultsafter TDT
(0.14MPa)
After TDT
(0.07MPa)
exp
an
sio
n
pla
stic
def
orm
ati
on
-0.5
-0.4
-0.3
-0.2
-0.1
0
0.1
0 10 20 30 40 50 60 70 80 90
Lo
ng
itu
din
al D
isto
rtio
n / m
m
Time / sec
34% sol.38% sol.42% sol.uncoated disc
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
What is the effects of blends
and additives?
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Green Sand TDT Specimen
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Casting Trial Stress on Specimen
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Casting Trial: Compression/Tension Model
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Casting Trial: Distortion Measurement Model
Designed to mimic parameters of TDT:
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
Thank You For Your Attention
AFS Sand Casting ConferenceOctober 20-22, 2014 – Indianapolis, IN USA
For additional information, please contact:
• Name: Sam Ramrattan
• Address: WMU – CEAS, Kalamazoo, MI 49008
• Phone: 269-276-3373
• Fax: 269-276-3353
• Email: [email protected]
• Web Site Address: wmich.edu/edmms/
