Transcript An Accelerated Method for Testing Soldering Tendency of Coated Pins H. Xu and T.T.

An Accelerated Method for Testing
Soldering Tendency of Coated Pins
H. Xu and T.T. Meek
University of Tennessee, Knoxville
Q. Han
Oak Ridge National Laboratory
The Goals of Research
 To develop an accelerated method for
testing die soldering of the core pins
 Using high intensity ultrasonic vibrations
 High relative velocity (>80 ips) between the pins
and the molten metal
 High pressure variation on the pin
 Simulating high speed high pressure die
casting
 To compare soldering tendencies of some
commercial coatings
Progress to Date
 An experimental setup has been developed using
high Intensity ultrasonic vibration (UV) to
accelerate die soldering
 More than 40 H13 pins were machined and coated
with four types of coatings
 Accelerated soldering was demonstrated in both
low carbon steel/Al and H13/A380 alloy systems
 The mechanisms were identified using SEM and
EDS analysis
The Main Results
 High intensity ultrasonic vibration can be used
for accelerating die soldering
 In the carbon steel/Al system, the onset of
soldering is 60 times faster with UV than that
without UV
 In the H13/A380 system, the onset of soldering
reaction is accelerated to 60 times
 Coating significantly reduces the soldering
tendency of the core pins
 It took less than 1 to 2 seconds to get the onset of
soldering reaction started on uncoated pins
 It took between 15 seconds to 2 minutes to get
the onset of soldering reaction started for the
commercially coated pins.
The Experimental Apparatus
Experimental system for the accelerated die soldering test . Key: (1) ultrasonic
generator; (2) controller for electric furnace; (3) melt temperature indicator; (4) pneumatically
operated device; (5) air inlet; (6) transducer; (7) booster; (8) horn; (9) core pin; (10) electric
furnace.
The Size of the Core Pin Used in the
Experiments
The core pin is about ¾ in diameter and 5 in long
Premium Quality AlSl H-13 Was
Used for Making the Core Pins
 Thyrotherm 2344 SUPRA ESR (Premium Quality
AISI H-13)
 The as-received material was soft annealed and
the hardness is 235 HB max.
Table 1 Chemical Composition of the premium H13 Steel
Element
Wt.%
C
0.40
Si
P
S
Cr
Mo
V
Fe
1.00
0.020max
0.003max
5.2
1.40
1.0
Balance
Heat Treatment Was Performed by a
Commercial Heat treating Company
1. Preheating (1) Place Load work into cold furnace and heat at a rate
150C/hour.(2) First preheating: Heat to 675C, Holding 45 minutes.(3) Second
preheating: Heat to 845C, Holding 45 minutes.
2. Austenitizing (1) Rapidly heat from second preheating temperature to
1030C. (2) Soak time is 44 minutes.
3. Quenching
(1) Pressurized gas quenching, the actual quenching pressure
is 2.1 bar. (2) Quenching rate is 35C/min between 1030C and 540C. (3)
Maintain pressurized gas quenching until 20 minutes later after the part
temperature reaches 65C.
4. Tempering
(1)The first temper occurs within 60 minutes of the quenching.
(2)First tempering: 540 C for 2 hours. (3)Second tempering: 605 C for 2
hours. (4)Third tempering: 600 C for 2 hours. (5)Fourth tempering: 595 C F
for 1 hour 45 minutes.
5. The final hardness range is 44-46 HRC
Heat Treatment Chart (Provided by
Paulo Product Company)
Four Types of Coating Were Coated by A
Commercial Coating Company
BALINIT® ALCRONA – (AlCrN)
BALINIT® FUTURA NANO – (TiAlN)
BALINIT® CrN
BALINIT® LUMENA – (Thicker TiAlN)
Die Soldering Is 60 Times Faster with UV
than that without UV in Fe/Al System
Al
0.5 S
Steel
It took more
than 1 min. to
get die soldering
without UV
Al
1.0 S
Steel
Intermetallics
Al
10 S
Steel
It took less than
1 s. to get die
soldering with
UV
Al
60 S
Steel
The Experimental Conditions for the
Accelerated Die Soldering Test Using
Premium H-13 Pins
 The H-13 pins were dipped in the A380 melt for different times
 The pin was quenched with compressed air after each dipping
 The intensity of the ultrasonic vibration was 30% of the
maximum vibration intensity
 The temperature of the melt was controlled around 665 C
(±15C)
 The fraction of the reaction area of the pin was measured using
optical microscopy (OM) and reaction product was analyzed
using SEM
 For comparison, the uncoated pin was also tested with and
without ultrasonic vibration at different dipping times
Soldering Occurs 60 Times Faster for
Uncoated H-13 Pins Subject to UV than
that without Subject to UV
Subject to UV
5 min.
Without Subject to UV
1 min.
1s
5s
A Soldering Area Fraction (SAF) is
Defined to Evaluate the Soldering
Resistance of an Coating
SAF: Soldered
area over the
total surface
area at the end
of a pin
The Commercial Coatings Have Stronger
Soldering Resistance than that of the
Uncoated H-13 Pins
Soldering area fraction (SAF) of the commercial
coatings at various dipping times
Dipping Time
(t)
1s
SAF of H13
Steel
1
5s
10s
15s
30s
60s
SAF of
ALCRONA
0.14
0.41
0.56
0.97
1
SAF of CrN
0.52
0.38
0.40
1
1
SAF of
FUTUEA NANO
0.14
0.22
0.58
0.92
0.97
0.003
0.03
SAF of
LUMENA
120s
240s
0.15
0.74
LUMENA Coating Shows the Best
Resistance to Soldering
Reaction area fraction of different coating according to the dipping time t (second)
The Soldering Resistance of the Coating
Seems to Be Correlated to the
Resistance of Local Coating Failure
EDS Analysis
results
showing
ALXFeXSiX
Intermetallic
phases
The tip of an H-13 pin with BALINIT® ALCRONA
coating after 5 seconds dipping with ultrasonic vibration
EDS Analysis results showing
the ALCRONA (AlCrN) Coating
More Slides on the Microstructure of
the Coated Pins at the Start of
Soldering Reactions
FYI
The Microstructure of H13 Steel (without
coating) After 30 seconds, 1 minute and 5
minutes Dipping without Ultrasonic Vibration
30 seconds
1 minute
5 minutes
No soldering
Soldering started
to occur
Completed soldering
The Microstructure of H13 Steel (without coating)
After 1 And 5 seconds Dipping With Ultrasonic
Vibration (Soldering Has Occurred at 1 s)
Optical Microscopy after 1 s
SEM Photo after 1 s
Optical Microscopy after 5 s
EDS Analysis results showing
the AlXSiXFeX intermetallic phase
The Microstructure of H13 Steel (With
BALINIT® ALCRONA Coating) After 5
Seconds Dipping
EDS Analysis results showing the ALXFeXSiX
Intermetallic phase
EDS Analysis results showing ALCRONA
(AlCrN) Coating
The Microstructure of H13 Steel (with
BALINIT® CrN coating) After 5 seconds
Dipping
EDS Analysis results
showing CrN Coating
EDS Analysis results showing
the ALXFeXSiX Intermetallic
phase
The Microstructure of H13 Steel (with BALINIT®
FUTURA NANO coating) After 5 seconds Dipping
EDS Analysis results showing FUTURA (TiAlN) Coating
EDS Analysis results showing the ALXFeXSiX
Intermetallic phase
The Microstructure of H13 Steel (with
BALINIT® LUMENA coating) After 60 seconds
Dipping
EDS Analysis results showing LUMENA (TiAlN) Coating
EDS Analysis results showing the ALXFeXSiX
Intermetallic phase