in situ tic formation using laser cladding
TRANSCRIPT
1
In-Situ TiC-Fe Deposition on Mild Steel Using Laser Cladding Process
Ali Emamian
Department of Mechanical and Mechatronics Engineering
November 18, 2009
2
Contents
• Introduction
• Motivation
• Objectives
• Experimental Approach and Procedure
• Results and Discussion
• Summary
• Future Work
3
Hard facing Methods
Coating Heat Treatment
Carburizing Composite coating
Metal matrix Bronizing
Ceramic coating
Matrix
Hard particles
Introduction
4
Laser cladding
is a method that can be used to form metal matrix composite
Creates a small heat affected zone Melts the powder and substrate Mixture of powder can be pre-place (pre-place
method) or fed by nozzle into the melt pool (dynamic blow method)
Introduction
5
Laser cladding (dynamic blow)
DP
DL
Introduction
6
Laser Cladding to produce composite coating
In-Situ ProcessDirect Adding carbide (ex-situ)
Introduction
7
What is “in-situ” laser cladding?
Heating combined pure powders under a laser heat source generates chemical reaction which produces the desired metal matrix of ceramic reinforcement;
Fe+Ti+C Fe + TiC
c Fe Ti
Matrix (Fe)
TiC
Introduction
8
In-situ process advantages
Particles are thermodynamically stable in the metal matrix
Reinforcing’ size can be controlled Rapid solidification can produce finely dispersed
ceramic particles High metal/ceramic bond strength (i.e. matrix can
transfer the applied stress, easily)
Introduction
9
Why TiC?
TiC has:
High melting point (3067º C)
High Young Modules High specific strength
High hardness (3000 HVN) 30% greater than WC
Low density (WC is almost 3 times heavier)
Introduction
10
Literature review (ex-situ) Ariely, Laser surface alloying of steel with TiC (1991). Tassin, Carbide-reinforced coatings on AISI 316 L stainless steel
by laser surface alloying (1995). Axen, Abrasive wear of TiC-steel composite clad layers on tool
steel (1992). Jiang, Laser deposited TiC/H13 tool steel composite coatings and
their erosion resistance (2007). Li, Micro structural characterization of laser-clad TiCp-reinforced
Ni-Cr-B-Si-C composite coatings on steel (1999). Wanliang, Microstructure of TiC dendrites reinforced titanium
matrix composite layer by laser cladding (2003). Hidouci, Microstructural and mechanical characteristics of laser
coatings (2000). Wu, Microstructure and mechanical properties at TiCp/Ni-alloy
interfaces in laser-synthesized coatings (2001).
Literature review
11
Literature review (In-situ) Cui, In situ TiC particles reinforced grey cast iron composite
fabricated by laser cladding of Ni–Ti–C system (2007). Wang, Microstructure and wear properties of TiC/FeCrBSi
surface composite coating prepared by laser cladding (2008). Yang, In-situ TiC reinforced composite coating produced by
powder feeding laser cladding (2006). Yan, In situ laser surface coating of TiC metal-matrix composite
layer (1996). Yang, S. Fabrication of in-situ synthesized TiC particles
reinforced composite coating by powder feeding laser cladding (2005).
Wu, X. In situ formation by laser cladding of a TiC composite coating with a gradient distribution (1999).
Yang1, In-situ TiC reinforced composite coating produced by powder feeding laser cladding (2006).
Wang, In situ synthesized TiC particles reinforced Fe based composite coating produced by laser cladding (2009).
Literature review
12
Have mostly focused on pre-place method Mainly used Ni or Co alloys as a binder Did not explain TiC formation mechanism Did not investigate the relationship between clad
microstructure and laser processing condition Produced carbides which are combination of Ni, Fe,
Co, Cr, B or Si. Variety of carbides other than TiC are produced in a complex solidification process
Motivation
Motivation
13
Objective
To form in-situ TiC in Fe matrix To form high quality clad (complete
metallurgical bonding between clad and substrate without porosity and crack)
Substrate
Clad
14
Milestones
To fully understand the effects of processing parameters on clad characteristics
To determine the Fe-TiC clad microstructure from laser processing parameters
To determine an optimum cladding condition to produce a high performance Fe-TiC
To evaluate hardness and wear resistance in relation to the clad processing condition
Objectives
15
Experimental set up
Chemical composition of powder: 24.9 wt% Ti, 5.1 wt% C, 70 wt% Fe
Powders’ size: maximum 0.04 mm Laser: Fiber Laser (1.1kW) iPG Diameter of laser beam: fixed at 2.5 mm Deposition method: Dynamic Blow Substrate: AISI 1030 (Carbon Steel)
Experimental approach
16
Ti/C ratio
Experimental approach
17
No Power
W
Scan speed
mm/s
Feed rate
g/min
1 250 2 8
2 250 4 8
3 250 6 8
4 400 2 8
5 400 4 8
6 400 6 8
7 650 2 8
8 650 4 8
9 650 6 8
10 650 8 8
11 650 10 8
12 650 12 8
13 650 16 8
No Power
W
Scan speed
mm/s
Feed rate
g/min
14 700 6 8
15 700 6 4
16 800 6 8
17 800 6 4
18 800 2 8
19 800 3 8
20 800 4 4
21 900 6 8
22 900 8 8
23 900 6 4
24 900 8 4
25 900 4 4
26 1000 4 4
No bond or clad
Clad-No bond
Clad with partial bond
High quality Clad
Results and discussion
Table of Results
18
0
20
40
60
80
100
120
140
160
180
0 0.005 0.01 0.015 0.02 0.025 0.03
E eff,
J/m
m2
PDD, g/mm2
High Quality Cladno clad or bondclad-no bondclad with partial bond
Zone I
Zone II
Zone III
High Quality Limit
L
PEnergy per unit area E
VD
2
2
L
L p
DRPowder depositiondensity PDD
VD D
Results and discussion
19
High quality limit
20
Un-bonded clad microstructure
Fe Matrix
TiC
Cross section
Results and discussion
21
Un-bonded clad
Region Ti conc.(wt%)
Fe conc.(wt%)
Dark grey particles 95.2 4.8
Region 1 8.7 91.3
Region 2 16.5 83.5
Results and discussion
22
Bonded clad Microstructure
Fe Matrix
TiC
Results and discussion
23
Bonded clad
Graphite
C
TiC
Longitudinal section
Results and discussion
24
0
20
40
60
80
100
120
140
160
180
200
0 0.002 0.004 0.006 0.008 0.01 0.012 0.014 0.016
E eff
J/m
m2
PDD, g/mm2
500 W
700 W
900 W
Quality Limit
Results and discussion
25
Cla
d
Substrate Results and discussion
26
Incr
easi
ng t
he s
can
spee
d
2 m
m/s
ec
12 m
m/s
ec10
mm
/sec
8 m
m/s
ec
6 m
m/s
ec4
mm
/sec
Clad Bottom
Clad BottomClad Bottom
Clad BottomClad Bottom
Clad Bottom
Laser power 900
Powder feed rate
4g/min
Results and discussion
27
2 m
m/s
ec
Incr
easi
ng t
he s
can
spee
d
Clad Top
4 m
m/s
ec6
mm
/sec
8 m
m/s
ec12
mm
/sec
10 m
m/s
ec
Clad TopClad Top
Clad TopClad Top
Clad Top
Results and discussion
Laser power 900
Powder feed rate 4g/min
28
Ternary phase diagram
2200C2400C
Results and discussion
29
TiC formation Fe powders melt Ti and C dissolve in Fe Ti and C react to form TiC layer
Material Fe Ti C
Melting point
°C1538 1668 3400
Results and discussion
TiCC
30
Fe
TiC
C
Ti
Increasing the temperature
TiC
Results and discussion
31
Summary
In-Situ TiC has been formed during the laser cladding process
It was shown that TiC morphology can be controlled by effective energy and powder deposition density
A map to predict the clad quality based on process parameters has been developed
32
Future work
Complete understanding of in-situ Fe-TiC coating , laser process parameters, microstructure and surface properties relationship
Process Control Optimization the powder composition Investigation of wear resistance behaviour
Future work
33
Future work
Process control
TiC morphology and
microstructure
Wear behaviour study
Future work
34
0
20
40
60
80
100
120
140
160
180
200
0 0.002 0.004 0.006 0.008 0.01 0.012 0.014 0.016
E eff
J/m
m2
PDD, g/mm2
500 W
700 W
900 W
Quality Limit
Process control High quality bonding and clad
area
Different microstructure and TiC morphology
Different scan speed
12
34
Future work
35
Wear investigation
1 2 3 4 n
Wear test machine
Investigation of surface, wear
modes
Future work
Comparison of wear behaviour
of different TiC morphology
Process control
36
Now70%Fe
Ti-45%at C
Future work70%Fe
Ti-50% at C
Future work70%Fe
Ti-55% at C
Graphite formation (self lubrication )
Ti+ C = TiC
Future work
Powder composition optimization
37
Fe Ti
C
70%Fe
Ti-55%CTi-50%CTi-45%C
38
Fe percentage decreasing
TiFe
C
70 60 50% Fe
50%C
55%C
Optimize the Ti:C ratio
Fe+C+TiC
39
Future work
Process optimization Microstructure characterization
• Wear behaviour investigation
Future work
40
Time table
Activity
Winter 2010
Spring 2010
Fall 2010 Winter 2011
Spring 2011
Fall 2011
Winter 2012
Investigation on optimum process parameters
Investigation on optimum compositions
TiC phase formation and morphology analyses
Wear resistance investigation and analysis-Process modification
Thesis writing
Defence
Future work
41
42
43
44
Y=ax+b
45
1400 C
4646
Y=ax+b
47
1000 C
48
49
50
51
52
Micro Hardness Results
0
200
400
600
800
1000
1200
1400
1600
0 100 200 300 400 500
Distance from interface of clad/substrate (um)
Har
dn
ess
(HV
N)
One layer clad (sample 23)
One layer clad (sample 25)
53
54
55
Las
er P
ower
Inc
reas
ing
56
In situ formation by laser beam
Methods:
Pre place Dynamic blowing
57Future work
Fe(γ)+G+TiC
