Highly Alloyed Titanium Alloys Produced by Low Cost Blended ...
Transcript of Highly Alloyed Titanium Alloys Produced by Low Cost Blended ...
Highly Alloyed Titanium Alloys Produced by Low Cost Blended Elemental Powder Metallurgy
ApproachM.V.Matviychuk1, V.S.Moxson1 , V.A.Duz1,
O.M. Ivasishin2, D.G. Savvakin 21‐ADMA Products, Inc. Hudson, OH, USA2‐Institute for Metal Physics, Kiev, Ukraine
ADMA Products, Inc. ©2013
1
Presentation overview
• PM BE approach for manufacturing the Ti alloys from TiH2 powder
• Highly‐alloyed Ti compositions (beta alloys)• High‐strength alloy Ti‐1Al‐8V‐5Fe shortoverview
• As‐sintered Properties of Ti‐1Al‐8V‐5Fe• Improvement of as‐sintered microstructure forTi‐1Al‐8V‐5Fe
• Effect of heat treatment (HT) and thermomechanical processing (TMP)
2ADMA Products, Inc. ©2013
PM BE approach for manufacturing the Ti alloys from TiH2 powder
TiH2, Alloying ElementsPowders
Blending Compaction Sintering
N Alloy Porosity, %
Grain Size, mkm
YS, MPA UTS, MPA El,%
1 Cp‐Ti 1 120 495 605 21
2 Ti‐6Al‐4V
1.5 150 885 975 12
ADMA Products, Inc. ©2013
3
Highly alloyed Ti compositions (beta alloys)
Widely used in aerospace, automotive and other industries due to:
‐ highest strength/density ratio among all titanium alloys
‐ mechanical properties can be changed within wide range by heat treatment
‐ homogeneous microstructure and properties within large cross sections
4ADMA Products, Inc. ©2013
Peculiarities of highly alloyed Ti compositions sintering
- higher content of alloying elements (higher volume part of master alloys)- more complicated phase transformations (e.g. high sensitivity to cooling conditions)- complicated chemical homogenization- increased residual porosity (up to 5%)
Process developed for alloys needed opt
5ADMA Products, Inc. ©2013
PM BE approach for manufacturing the highly alloyed Ti alloys from TiH2powder
Porosity, % GrainSize,μm
YS, MPa UTS,MPa
El., % RA, %
As‐sintered 2 82 1005 1100 10.6 17.9
STA 2 82 1115 1250 5.2 11.0
Porosity, % GrainSize,μm
YS, MPa UTS,MPa
El., % RA, %
As‐sintered 1.5 100 1140 1244 4.87 9.21
Aging 1.5 100 1200 1304 6.8 10.3
Ti‐10V‐2Fe‐3Al
Ti‐5Al‐5V‐5Mo‐3Cr
TiH2, Alloying ElementsPowders
Blending Compaction Optimize Sintering
Heat Treatment
6ADMA Products, Inc. ©2013
• Is it possible to produce the high‐strength Ti alloys with UTS>1400 MPA by Powder Metallurgy?
7ADMA Products, Inc. ©2013
Highly alloyed Ti‐compositions• Ti‐1Al8V5Fe – a high‐strength alloy developed in 1950’s
ADMA Products, Inc. ©2013
8
YS, MPA UTS, MPA El,% RA, %
1380 1448 6.0 12.0
Guaranteed STA room‐temperature properties
V Al Fe O N C Fe
7.5‐8.5 0.8‐1.3 4.0‐6.0 0.25‐0.5
0.07 0.05 4.0‐6.0
Chemical compositions
Beta Transus: 830 oC
Effect of STA on tensile propertiesMaterials Properties HandbookTitanium Alloysedited by Gerhard Welsch
9ADMA Products, Inc. ©2013
TTT diagrams
Mo eq. 1023 = 9.5
Mo eq. 5553 =8.15Mo eq. 185 = 18 James D. Cotton,
Proceedings of 11th World
Conference on
Titanium Ti‐2007 (Kyoto, Japan). ‐pp.471‐475
D. Eylon,Beta Titanium Alloys in the 1990's
Materials Properties Handbook: Titanium Alloys edited by Gerhard Welsch
10ADMA Products, Inc. ©2013
Effect of alloying elements on shrinkage
11
0 200 400 600 800 1000 1200 1400
-0,10
-0,08
-0,06
-0,04
-0,02
0,00
0,02
L/
L
Temperature, °C
CpTiTi-185
Ti-5553Ti-1023
ADMA Products, Inc. ©2013
As‐sintered Microstructure of Ti‐185TiH2, Alloying
ElementsPowders
Blending Compaction Sintering
‐Low tensile properties‐High brittleness‐Porosity 3%
12ADMA Products, Inc. ©2013
Improvement of as‐sintered microstructure and properties
Regime
Porosity, %
Grain size, mkm
T1 2.5 110-137
T2 1.9 136-204
T3 2.7 126-166
T4 2.55 156-217
Porosity,%
GrainSize,μm
YS,MPa
UTS, MPa El.,%
RA,%
Oxygen,%
Regularsintering
3 50 ‐ 875 ‐ ‐ 0.4
Low poroussint.
1.9 160 862 925 ‐ ‐ 0.33
Ti‐1Al‐8V‐5Fe
T1
T2
T3
T4
TiH2, Alloying ElementsPowders
Blending Compaction Low porousSintering
T1
13ADMA Products, Inc. ©2013
14
Thermo‐Mechanical processing of Ti‐1Al‐8V‐5Fe
Ø=90mm
ADMA Products, Inc. ©2013
Ø=16mmHot rolling
TiH2, Alloying ElementsPowders
Blending Compaction Sintering Post Processing
15
Density: 97%100%
Effect of thermo‐mechanical processing on improvement of mechanical
properties of Ti‐185
As‐sintered As‐rolled
YS, MPa UTS, MPa El., %
As-Sintered 857 ± 15
As-Rolled 1192 ± 13 1283 ± 12 18 ± 1.5
Rolled + STA1
1489 ± 6 1535 ± 4 5 ± 1.0
Rolled + STA2
1620 ±16
1668 ± 15 4.7 ± 0.8
Rolled + STA3
1654 ±10
1689 ± 13 4 ± 1.8
The total reduction ratio for the rod‐rolling process was 31:1
ADMA Products, Inc. ©2013
RBF S‐N curves of Ti‐185
The RBF was conducted at 10,000 RPM or166.6 Hz.
ADMA Products, Inc. ©2013
16
Optimized properties
YS, MPa UTS, MPa El., %
As-Sintered 857 ± 15As-Rolled 1192 ± 13 1283 ± 12 18 ± 1.5
Rolled + STA4 1585 1654 8
Guaranteed STAroom‐temperature
properties1380 1448 6
17ADMA Products, Inc. ©2013
18
Conclusion• Highly‐alloyed titanium compositions with strength more
then 1400 MPa (Ti‐1Al‐8V‐5Fe) can be successfully sinteredvia a novel low cost powder metallurgy route using titaniumhydride powder. It is especially important in case of alloysthat are difficult to produce via ingot metallurgy.
• The microstructures of Ti‐1Al‐8V‐5Fe were homogeneousacross the entire cross section, and no segregation wasobserved.
• The controlled formation of fine grains, reduced porosityduring alloy sintering, properly selected post‐sintering heattreatment and thermo‐mechanical processing parametersallow attainment of desirable properties meeting highstrength requirements.
ADMA Products, Inc. ©2013