european school “bulk metallic glasses” torino, september...
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European School“Bulk metallic glasses”Torino, September 2006
Influence of Ti content and partial crystallization on mechanical properties of
a Zr-base bulk metallic glass
Materials Characterisation & Processing GroupMaterials Characterisation & Processing GroupWaterford Institute of TechnologyWaterford Institute of Technology
Marie-Laure Vaillant
Materials Characterisation & Processing Group Materials Characterisation & Processing Group –– Waterford Institute of TechnologyWaterford Institute of Technology
Materials
Zr62-xTixCu20Ni8Al10 with x = 2.5and x = 3.5
Rods of 3 mm diameter manufactured by copper mould casting in Dresden* in two different states:
As-cast Annealed
Study of the influence on mechanical properties of - Ti content
- Partial crystallisation
*U. Kühn et al. Acta Mat. In Press (2006)
Materials Characterisation & Processing Group Materials Characterisation & Processing Group –– Waterford Institute of TechnologyWaterford Institute of Technology
DSC analysis
500 550 600 650 700 750 800 850
Nor
mal
ized
exo
ther
mic
hea
t flo
w, a
.u.
Temperature, K
Ti 3.5%
Ti 3.2%
Ti 2.9%
Ti 2.5%
TA
Materials Characterisation & Processing Group Materials Characterisation & Processing Group –– Waterford Institute of TechnologyWaterford Institute of Technology
Annealed samples
XRD scans
20 30 40 50 60 70 80
(200
000)
(110
010)
(101
000)
(111
100)
(111
000)
(111
101)
(210
001)
(110
000)
Inte
nsity
, a.u
.
2Θ, Degrees
Ti 2.5%
Ti 2.9%
Ti 3.5%
Ti 3.2%
(100
000)
TEM
Size ofquasicrystals:
≈200 nm
≈50 nm
200 nm
200 nm
Materials Characterisation & Processing Group Materials Characterisation & Processing Group –– Waterford Institute of TechnologyWaterford Institute of Technology
Compression tests - Parameters
Temperature: Room temperature
Strain rate: 4.4 × 10-4 s-1
Testpieces: h ≈ 5.6 mmØ ≈ 3 mm
Testpieces NOT machined
Materials Characterisation & Processing Group Materials Characterisation & Processing Group –– Waterford Institute of TechnologyWaterford Institute of Technology
Compression tests
-200
0
200
400
600
800
1000
1200
1400
1600
1800
2000
-0,01 0 0,01 0,02 0,03 0,04 0,05 0,06
D1_K189D2_K188
Stre
ss [M
Pa]
Strain [-]
1891 MPa1728 MPa
As-castAnnealedBrittleness Plasticity
2.5 % Ti
Materials Characterisation & Processing Group Materials Characterisation & Processing Group –– Waterford Institute of TechnologyWaterford Institute of Technology
-200
0
200
400
600
800
1000
1200
1400
1600
1800
2000
0 0,01 0,02 0,03 0,04 0,05 0,06
D1_K194D1_K195
Stre
ss [M
Pa]
Strain [-]
Compression tests
1918 MPa1655 MPa
As-castAnnealedBrittleness Plasticity
3.5 % Ti
Materials Characterisation & Processing Group Materials Characterisation & Processing Group –– Waterford Institute of TechnologyWaterford Institute of Technology
Compression tests - Results
2.5% of TiAs-cast
Annealed
Yieldstrengthσy (MPa)
E(GPa)
σf(MPa)
Plasticstrainεpl (%)
Fracturestrainεf (%)
As-cast
Annealed
65.3 1580 1728 1.95 4.81
72.6 - 1891 - 2.93
3.5% of Ti64.8 1350 1655 2.12 4.96
72.2 - 1918 - 3.25
Materials Characterisation & Processing Group Materials Characterisation & Processing Group –– Waterford Institute of TechnologyWaterford Institute of Technology
Fracture surface
AS-CAST samples (exhibited some plasticity)
43°
Comp. axis
Materials Characterisation & Processing Group Materials Characterisation & Processing Group –– Waterford Institute of TechnologyWaterford Institute of Technology
Fracture surface
As-cast samples(exhibited some plasticity)
Smooth regionVein-like pattern
River-like pattern
Materials Characterisation & Processing Group Materials Characterisation & Processing Group –– Waterford Institute of TechnologyWaterford Institute of Technology
Fracture surface
As-cast samples (exhibited some plasticity)
Materials Characterisation & Processing Group Materials Characterisation & Processing Group –– Waterford Institute of TechnologyWaterford Institute of Technology
Fracture surface
Annealed samples(exhibited brittleness)
*Chang et al. Mat. Sci. Eng. A 396 (2005) 423-428
Quasicrystal:Vf = 48 %, sizeQC= 200 nm (2.5 at% Ti)Vf = 63 %, sizeQC= 50 nm (3.5 at% Ti)
Materials Characterisation & Processing Group Materials Characterisation & Processing Group –– Waterford Institute of TechnologyWaterford Institute of Technology
Fracture surface
Annealed samples(exhibited brittleness)
Materials Characterisation & Processing Group Materials Characterisation & Processing Group –– Waterford Institute of TechnologyWaterford Institute of Technology
Comparison with other materials
Young's Modulus (GPa)10 100 1000
Ela
stic
Lim
it (M
Pa)
1
10
100
1000
10000
Lead Antimony Alloy
Tungsten
Platinum Iridum Alloy
Lead Tin Alloy Solder
Cast Magnesium
Tin Antimony AlloyPlatinum, Commercial Purity
Cast Nickel Tungsten Alloy
Zr59.9Ti2.5Cu20Ni8Al10
La50Al25Cu25
La55Al35Cu10
Pd40Cu30Ni10P20
Zr55Al15Ni10Cu20 Ti50Be40Zr10Fe81.1C13.8Si5.1
Fe40Ni40P14B6
12% Nickel silver (cast)
70/30 Copper-nickel (cast)
Zinc Copper Alloy
Grey (Flake graphite) cast iron (BS grade 150)
Carbon steel, AISI 1117 (normalised)Wrought aluminium alloy (6061-T4)
Materials Characterisation & Processing Group Materials Characterisation & Processing Group –– Waterford Institute of TechnologyWaterford Institute of Technology
Comparison with other BMG
Young's Modulus (GPa)20 50 100 200
Ela
stic
Lim
it (M
Pa)
200
500
1000
2000
5000
Zr59.9Ti2.5Cu20Ni8Al10
Zr41.25Ti13.75Cu12.5Ni10Be22.5
Ti50Be40Zr10
Ti50Ni20Cu25Sn5
Zr55Al15Ni10Cu20
Fe40Ni40P14B6
Fe81.1C13.8Si5.1
Pd64Ni16P20
Pt60P25Ni15Pd40Cu30Ni10P20
LM2
Mg69Y21Cu10
Mg90Ca2.5Ni7.5
La55Al35Cu10
La50Al25Cu25
Materials Characterisation & Processing Group Materials Characterisation & Processing Group –– Waterford Institute of TechnologyWaterford Institute of Technology
ConclusionResidual stresses Testpieces not machinedWith the exception of the sample annealed at 480°C, the σ – εbehaviour indicated the existence of net compressive residual stress.
Ti content: no significant influence on mechanical properties, i.e. for 2.5 / 3.5 at.%.Comparing as-cast and annealed
As-cast Annealed
E (GPa)
Yield strength σy (MPa)σf (MPa)
Plastic strain εpl (%)
Fracture strain εf (%)
65 721450 -1700 1900
2 ≈04.9 3.1
Materials Characterisation & Processing Group Materials Characterisation & Processing Group –– Waterford Institute of TechnologyWaterford Institute of Technology
Future work
Influence of size and volume fraction of quasicrystals on mechanical properties for this Zr-base BMG
Materials Characterisation & Processing Group Materials Characterisation & Processing Group –– Waterford Institute of TechnologyWaterford Institute of Technology
Thanks for your attentionThanks for your attention
Materials Characterisation & Processing Group Materials Characterisation & Processing Group –– Waterford Institute of TechnologyWaterford Institute of Technology
Compression tests
-0.01 0 0.01 0.02 0.03 0.04 0.05 0.06 0.07
Strain [-]
0
200
400
600
800
1000
1200
1400
1600
1800
2000
Stre
ss [M
Pa]
D1_K189D1_K195D1_K194D2_K188
As-castAnnealed
Ti 2.5%Ti 2.5%
Ti 3.5%Ti 3.5%
Materials Characterisation & Processing Group Materials Characterisation & Processing Group –– Waterford Institute of TechnologyWaterford Institute of Technology
Volume fraction of quasicrystals
Volume fraction of quasicrystals
Ti content Before compression
Aftercompression
2.5 %
3.5 %
Estimate of quasicrystals volume fraction in the annealed samples from DSC analysis: