2. Metallography is the study of microstructure, how it is
produced by composition and processing control, and the
relationship between microstructure, mechanical and
physical properties, and performance or service behavior.
To examine the microstructure, we must prepare
specimens properly so that the true structure, free of
artifacts due to preparation, can be observed and
properly identified, measured and interpreted.
3. Microstructure is the structure of a suitably
prepare specimen as revealed by a microscope
Microstructure consists of phases and/or
constituents.
A phase is a physically homogeneous, mechanically
separable portion of a material system.
A constituent is a phase or combination of phases,
which occurs in a characteristic configuration in an
alloy microstructure.
4. Grains are individual crystals within a metal.
Most metals are polycrystalline, that is, made up of many
individual crystals, but some are “single crystals” and
have no internal grain boundaries.
Grain boundaries are interfaces separating adjacent
grains where the orientation of the crystal lattice changes
from that of one grain to that of the other. The orientation
difference is large. Sub-grain boundaries exhibit a small
misorientation across the boundary.
5. Grain size is the dimension of the grains or
crystals in a polycrystalline metal exclusive of
twinned regions and sub-grains, when present.
Although grains are three-dimensional in space,
the size is estimated on the two-dimensional
plane-of-polish for a large aggregate of grains
(to provide statistical precision).
6. 5/16 Sieve 4 Sieve
8 Sieve
14 Sieve
Separation of
grains by sieving
after liquid metal
embrittlement of
Brass in Hg
3.3 mm
3.3 mm
3.3 mm
3.3 mm
7. To see the true microstructure we generally will
cut a specimen from a larger section (the specimen
must be representative) in a manner to minimize
damage; encapsulate the specimen in a polymeric
resin; grain and polish the specimen with a
damage-free surface; etch the specimen with a
suitable reagent (non-cubic metals may be
examined with polarized light unetched); and
document the images.
8. Medium and large format Delta™ abrasive
saws with wheels 10 to 18 inch diameter.
9. With the chop cutter the contact area, when cutting a round bar, is very small
initially, increases to a maximum, then decreases to a point contact. Thus, the
pressure varies through the cut. This reduces cutting efficiency and increases heat
generation. Orbital cutting reduces this variation. When the wheel lifts out of the
cut, coolant flows into the cut which reduces sectioning damage.
10. Great versatility and a multitude of optional
features make IsoMet® precision saws one of the
labs best tools. A wide range of blades, both
consumable and non-consumable, are available.
11. Modern presses, such as the SimpliMet® family of presses, have built in
heating and cooling systems. Cooling a thermosetting polymer back to near
ambient temperature reduces or eliminates shrinkage gaps, which improves
edge retention and minimizes contamination and bleed out problems.
13. The decarburized surface of this heat treated specimen of 440A
stainless steel cannot be measured accurately due to rounding;
the specimen was not mounted (Fry’s Reagent).
14. Semi-automatic (left) or fully automatic (right) systems not only improve
productivity but they produce much higher quality specimens with better
edge retention and freedom from artifacts – consistently.
15. 8 and 10” (200 and 250 mm) 12” (300 mm)
• Z-Axis Removal Control; • Under-Bowl Cooling
• Head Speeds 30,40,50,60,150 rpm
• Complementary or Contra; • Fully Programmable
16. Magnetic disk systems introduce convenience in multiple-user labs while
reducing platen inventory.
18. Alumina suspensions are redefined by sol-gel MasterPrep alumina (0.05-µm
particle size). Unlike calcined alumina suspensions, MasterPrep suspensions
are totally free of agglomerates. It markedly outperforms all other alumina
abrasives and has none of the problems associated with colloidal silica.
19.
20. Surface deformation from abrasive sectioning (left side, see arrows) of
commercial purity (CP) Ti, ASTM F 67, Grade 2 (UNS R50400), annealed
at 1038 °C, revealed using modified Weck’s reagent and cross polarized
light plus sensitive tint. Original image at 100X. The magnification bar is
100 µm long. Mechanical twins can be seen along the top surface (see
vertical arrow) which may have been caused by the clamping pressure.
21. Sectioning damage at cut edges of fine silver (100% Ag) revealed by etching
with 10% NaCN and 10% ammonium persulfate.
22. Residual damage from shearing 14-karat gold (58% Au) revealed by etching
with 10% NaCN and H2O2 (30% conc).
23. Residual grinding damage in fine silver (100% Ag) revealed by etching with
10% NaCN and 10% ammonium persulfate.
25. Surface Abrasive/Size
Load Lb. (N)/
Specimen
Base Speed
(rpm)/Direction
Time
(min:sec)
CarbiMet
paper
180, 240 or 320
(P180, P240, or P400)
SiC, water cooled
6 (27)
240 – 300
Comp.
Until plane
UltraPol™
9- m MetaDi®
Supreme diamond
suspension
6 (27)
120 – 150
Comp.
5:00
TriDent™
3- m MetaDi Supreme
diamond suspension
6 (27)
120 – 150
Comp.
4:00
ChemoMet
®
0.05- m MasterPrep™
alumina suspension
6 (27)
120 – 150
Contra*
2:00
Based on 1 ¼ mount size *Use contra only with low-speed heads (<100 rpm)
26. Surface Abrasive/Size
Load Lb.
(N)/
Specimen
Base Speed
(rpm)/Direction
Time
(min:sec)
CarbiMet paper
240- (P280) grit SiC
Water cooled
5 (22)
240
Comp.
Until
plane
UltraPol cloth
9- m MetaDi Supreme
diamond suspension
5 (22)
150
Comp.
5:00
TriDent cloth
3- m MetaDi Supreme
diamond suspension
5 (22)
150
Comp.
4:00
TriDent cloth
1- m MetaDi Supreme
diamond paste
5 (22)
120
Comp.
2:00
MicroCloth pad
0.05- m MasterMet®
Colloidal silica
5 (22)
120
Contra
1:30
27. Equiaxed alpha grains at the surface of a super-pure (SP) aluminum specimen
etched with Barker’s reagent, 30 V dc, 2 min. Note the damage from sectioning
along the surface (top edge); (polarized light + sensitive tint, 50X).
28. As-cast 206 aluminum (Al – 4.4% Cu – 0.3% Mg – 0.3% Mn) tint etched
with Weck’s reagent and viewed with crossed polarized light plus a
sensitive tint filter. Magnification bar is 50 µm long.
29. Wrought 2024-F aluminum (Al – 4.4% Cu – 1.5% Mg – 0.6% Mn) bar (28.5
mm diam.) showing the grain structure and intermetallics. Magnification
bar is 200 µm long. Anodized with Barker’s reagent (30 V dc, 2 min.).
Transverse plane.
31. Weld Base
Microstructure of a friction stir weld in 2519 aluminum (Al – 5.8% Cu – 0.3% Mn
– 0.3% Mg – 0.06% Ti – 0.1% V – 0.15% Zr) etched with Weck’s reagent and
viewed with polarized light plus sensitive tint. Original at 100X. The magnification
bar is 100 µm long.
32. Surface Abrasive/Size
Load Lb.
(N)/
Specimen
Base Speed
(rpm)/Direction
Time
(min:sec)
CarbiMet
320- (P400) grit SiC
Water cooled
6 (27)
240
Comp.
Until
plane
UltraPol Cloth
6- m MetaDi Supreme
diamond suspension
6 (27)
150
Comp.
5:00
TexMet® 1500Pad
3- m MetaDi Supreme
diamond suspension
6 (27)
150
Comp.
3:00
TriDent Cloth
1- m MetaDi Supreme
diamond suspension
6 (27)
120
Comp.
2:00
MicroCloth Pad
0.05- m MasterMet
Colloidal silica
5 (22)
120
Contra
2:00
33. Microstructure of hot extruded, cold worked and annealed (500 °C) high-
purity copper etched with klemms III and Beraha’s PbS tint etches and
viewed with polarized light plus sensitive tint, 46 HV.
Klemm’s III Beraha’s PbS
100 µm 100 µm
34. As-Cast, Klemm’s II Wrought, Beraha’s PbS
Microstructure of as-cast and hot extruded and cold drawn (interior)
phosphorous-deoxidized copper tint etched and viewed with
polarized light plus sensitive tint.
200 µm
100 µm
35. Bright Field Nomarski DIC, Bar is 100 µm
Microstructure of sand-cast Cu – 4% Sn etched with Beraha’s PbS tint etch
revealing the dendritic cast structure. 63 HV.
200 µm 100 µm
36. Cu–30% Zn, HE, CR 50%, Annl. 704 °C – 30 min.
Klemm’s III, Original at 50X Beraha’s PbS, Original at 50X
Microstructure of wrought cartridge brass, Cu – 30% Zn, cold reduced 50% and
annealed at 704 °C (1300 °F) – 30 min. producing a fully recrystallized, and
grown, equiaxed FCC grain structure with annealing twins. Polarized light and
sensitive tint.
37. 100 µm 100 µm
Bright Field Nomarski DIC
Microstructure of Muntz Metal, Cu – 40% Zn, heated to 716 °C (1320
°F), held 1 h and water quenched producing still more beta phase
(colored), of larger size, and with less preferred orientation. Nomarski
DIC of this specimen tint etched with Klemm’s I reagent reveals the
grain and twin structure in the un-etched alpha phase (not colored).
38. Wrought, solution annealed and aged beryllium copper, Cu – 1.8% Be –0.3% Co. Heat treatment: 790
°C (1454 °F), hold 1 h, oil quench, age at 315 °C (600 °F) for 2 h. Hardness 380 HV. Swab etched with
equal parts ammonium hydroxide and hydrogen peroxide (3% conc.). Polarized light brings out the
diffuse “criss-cross” markings due to the fine ’ precipitates. There is some over-aging at the grain
boundaries where can be found. Original at 200X. Crossed polars + sensitive tint.
39. 20 µm
Polarized Light Nomarski DIC
1 martensite formed in fcc alpha phase in a Cu – 26% Zn – 5% Al shape
memory alloy (both un-etched).
40. Surface Abrasive/Size
Load Lb.
(N)/
Specimen
Base Speed
(rpm)/Direction
Time
(min:sec)
CarbiMet paper
240- (P280) grit SiC
Water cooled
6 (27)
240
Comp.
Until
plane
BuehlerHercules™ H
Rigid grinding disk
9- m MetaDi Supreme
diamond suspension
6 (27)
150
Comp.
5:00
TriDent cloth
3- m MetaDi Supreme
diamond suspension
6 (27)
150
Comp.
3:00
MicroCloth pad
0.05- m MasterPrep
alumina suspension
6 (27)
120
Contra
1:30
41. Line Pipe Alloy Coated with Three Layers of Polymer for Protection from Sea
Water Corrosion (Klemm’s I reagent, polarized light).
42. Ferrite grains in lamination sheet steel revealed using Klemm’s I tint etch. This is
a duplex condition where there are much larger grains near the surface.
Magnification bar is 100 µm in length (polarized light plus sensitive tint).
Mount
43. Twinned austenitic grain structure of wrought, annealed Fe – 39% Ni color etched
with Beraha’s sulfamic acid solution (100 mL water, 3 g potassium metabisulfite, 2
g sulfamic acid) and viewed with polarized light plus sensitive tint, 100X.
44. Twinned austenitic grain structure of solution annealed, wrought Hadfield
manganese steel (Fe – 1.12% C – 12.7% Mn – 0.31% Si) tint etched with Beraha’s
sulfamic acid reagent (100 mL water, 3 g potassium metabisulfite and 2 g sulfamic
acid) and viewed with polarized light plus sensitive tint, 100X.
45. Upper bainite (blue and white) and as-quenched martensite (brown) in 5160 alloy steel (Fe
– 0.6% C - 0.85% Mn – 0.25% Si – 0.8% Cr) that was austenitized at 830 °C (1525 °F) for
30 min., isothermally held at 538 °C (1000 F°) for 30 sec to partially transform the
austenite, and then water quenched (untransformed austenite forms martensite). Etched
with aqueous 10% Na2S2O5.
46. Low-carbon, “lath” martensite in an over-austenitized specimen of AerMet 100 (Fe – 0.23% C – 13.4%
Co – 11.1% Ni – 3.1% Cr – 1.2% Mo). The grain size was coarsened by the heat treatment (1093 °C,
AC, age at 675 °C for 6 h, AC) making it easier to see the lath structure. Etched with aqueous 10%
sodium metabisulfite and viewed with polarized light plus sensitive tint. Original magnification was
100X. AerMet is a trademark of Carpenter Technology Corp., Reading, Pennsylvania.
47. Example of “butterfly” martensite (low carbon martensite) formed on the polished surface
of a specimen of High-Expansion 22-3 (Fe – 0.1% C – 0.5% Mn – 0.2% Si – 3.1% Cr – 22%
Ni) alloy steel when cooled to –73 °C. Unstable austenite transformed to martensite with its
characteristic shear which is visible on a free surface using Nomarski DIC ( not etched).
25 µm
48. Surface Abrasive/Size
Load Lb. (N)/
Specimen
Base Speed
(rpm)/Direction
Time
(min:sec)
CarbiMet paper
240- (P280) grit SiC
Water cooled
6 (27)
240
Comp.
Until
plane
UltraPol cloth
9- m MetaDi Supreme
diamond suspension
6 (27)
150
Contra
5:00
TriDent cloth
3- m MetaDi Supreme
diamond suspension
6 (27)
150
Contra
5:00
ChemoMet pad
0.05- m MasterPrep
alumina suspension
6 (27)
120
Contra
2:00
49. Microstructure of Custom Flo 302-HQ austenitic stainless steel (Fe - <0.08% C – 18% Cr –
9% Ni – 3.5% Cu) in the hot rolled and solution annealed condition after tint etching with
Beraha’s BI reagent. The structure is equiaxed, twinned FCC austenite. The faint vertical
lines are from alloy segregation (longitudinal direction is vertical). Viewed with polarized
light plus sensitive tint. The magnification bar is 100 µm long.
50. Microstructure of wrought 7-Mo duplex stainless steel (Fe - <0.1% C – 27.5% Cr –
4.5% Ni – 1.5% Mo) solution annealed and then aged 48 h at 816 °C to form sigma.
Electrolytic etching with aqueous 20% NaOH (3 V dc, 10 s) revealed the ferrite as
tan, the sigma orange, while the austenite was not colored. Magnification bar is 10
µm in length.
51. Dendritic microstructure of Alloy 718 in the as-cast condition after tint
etching with Beraha’s reagent. Note the white particles are delta phase.
The magnification bar is 200 µm long.
52. Microstructure of wrought, solution annealed and double aged (about 42 HRC)
Waspaloy, a nickel-based superalloy (Ni – 0.06% C – 19.5% Cr – 4.2% Mo – 13.5% Co
– 3% Ti – 1.35% Al – 0.07% Zr –0.005% B - <2% Fe) tint etched with Beraha’s BIV
reagent revealing twinned austenitic grains. Viewed in bright field. The magnification
bar is 100 µm long.
53. Surface Abrasive/Size
Load Lb. (N)/
Specimen
Base Speed
(rpm)/Direction
Time
(min:sec)
CarbiMet paper
240- (P280) grit SiC
Water cooled
6 (27)
240
Comp.
Until
plane
UltraPol cloth
9- m MetaDi Supreme
diamond suspension
6 (27)
150
Comp.
5:00
TexMet 1500 pad
3- m MetaDi Supreme
diamond suspension
6 (27)
150
Comp.
4:00
TriDent cloth
1- m MetaDi Supreme
diamond suspension
6 (27)
120
Comp.
3:00
ChemoMet pad
0.05- m MasterPrep
alumina suspension
6 (27)
120
Contra
2:00
55. Microstructure of austempered ductile iron tint etched with Beraha’s CdS
reagent containing large graphite nodules (arrow), bainite (blue and
brown) and retained austenite (white) when viewed with polarized light
plus sensitive tint. Original at 500X.
56. As-cast NiHard cast iron (Fe – 2.98% C – 0.64% Mn – 0.85% Si – 4.4% Ni – 2.34% Cr)
containing cementite (white), retained austenite (light brown), manganese sulfides (gray
particles) and plate martensite “needles” (light blue and medium blue) after tint etching
with Beraha’s CdS reagent and viewing with polarized light plus sensitive tint, 1000X.
57. Surface Abrasive Load, lb. rpm Minutes
Waterproof
Discs
220-320-grit
(P240-P400) SiC
3 (13 N) 150-240
(comp.)
Until Plane
TexMet 1500
Pad
9-µm MetaDi
Diamond Paste*
3 (13 N) 150-240
(comp.)
5
TexMet 1500
Pad
3-µm MetaDi
Diamond Paste*
3 (13 N) 150-240
(comp.)
3
TexMet 1500
Pad
1-µm MetaDi
Diamond Paste*
3 (13 N) 150-240
(comp.)
2
ChemoMet
Pad
MasterPrep Sol-Gel
Alumina
2 (9) 100-150
(comp.)
2
*Use water as the lubricant, but keep the surface relatively dry
Comp. = complementary ( both the head and platen rotating counterclockwise)
58. For 18-karat gold alloys, and similar highly noble
precious metals: it is necessary to use an attack-polish
agent in the MasterPrep alumina abrasive step. Mix 10
mL of the attack-polish solution with 50 mL of
MasterPrep alumina slurry. The attack-polish agent
can be: H2O2 (30% conc.), or aqueous 5-20% CrO3, or
aqueous 10% oxalic acid, etc.
59. Microstructure of as-cast pure ruthenium, as polished, viewed in polarized light
plus sensitive tint revealing a mixture of equiaxed and columnar HCP grains and
some small shrinkage cavities (black). The magnification bar is 200 µm long.
60. Bright Field Nomarski DIC
Microstructure of Spangold, Au – 19% Cu – 5% Al, a new jewelry alloy using
martensite formation to create a rippled effect (“spangles”) on the surface. The
specimen was polished, heated to 100 °C for 2 minutes, and quenched in water to
form martensite, which produces shear at the free surface. This roughness can be
seen using Nomarski DIC without etching. The criss-crossed pattern is produced by
forming martensite, polishing and then forming new martensite.
61. Microstructure of Spangold, Au – 19% Cu – 5% Al, a new jewelry alloy using martensite
formation to create a rippled effect (“spangles”) on the surface. The specimen was
polished, heated to 100 °C for 2 minutes, and quenched in water to form martensite,
which produces shear at the free surface. This roughness can be seen using Nomarski
DIC without etching. The criss-crossed pattern is produced by forming martensite,
polishing and then forming new martensite. The magnification bar is 50 µm long.
62. Microstructure of Spangold, Au – 19% Cu – 5% Al, a new jewelry alloy using
martensite formation to create a rippled effect (“spangles”) on the surface. The
specimen was polished, heated to 100 °C for 2 minutes, and quenched in water to form
martensite, which produces shear at the free surface. This roughness can be seen using
Nomarski DIC without etching. The criss-crossed pattern is produced by forming
martensite, polishing and then forming new martensite.
63. Microstructure of wrought sterling silver ( 92% Ag) revealed
by etching with equal parts of ammonium hydroxide and
hydrogen peroxide (3% conc.)
64. Microstructure of fine silver ( 100% Ag) revealed by etching with
10% NaCN and 10% ammonium persulfate.
65. Bright Field Polarized Light
14-karat gold (52% Au) prepared without attack polishing, etched with
equal parts of 10% NaCN and hydrogen peroxide (30% conc.) and viewed
with bright field and with polarized light.
66. Previous specimen of 14-karat gold examined with polarized light plus a
sensitive tint filter. The color effect comes from the surface roughness
created by the grain-contrast etch.
67. The 14-karat gold specimen after attack polishing and re-etching with
10% NaCN and H2O2 (30% conc.) revealing a “flat” etch.
68. 14-karat gold, attack polished and etched with equal parts of 10% NaCN
and H2O2 (30% conc.) and viewed with bright field and Nomarski DIC.
Bright Field Nomarski DIC
69. 18-karat gold (75% Au – 22% Ag – 3% Ni) after attack polishing and
etching with equal parts of 10% NaCN and H2O2 (30% conc.).
70. Bright Field Nomarski DIC
18-karat gold (75% Au – 22% Ag – 3% Ni) after attack polishing and
etching with equal parts of 10% NaCN and H2O2 (30% conc.) and
viewed with bright field and Nomarski DIC.
71. As-cast Paliney 7 (35% Pd – 30% Ag – 14% Cu – 10% Pt – 10% Au – 1%
Zn) etched with aqua regia revealing a dendritic structure.
72. Solution annealed and aged 44% Pd – 38% Ag – 1% Ni – 16% Cu
etched with equal parts of 10% NaCN and 10% ammonium
persulfate .
73. Solution annealed and aged 44% Pd – 38% Ag – 1% Ni – 16% Cu etched
with a 10 to 1 mix of HCl and HNO3. This etch brings up the grain
boundaries in the matrix phase. Note the lamellar nature of the second-phase
constituent.
74. Surface Abrasive/Size
Load Lb.
(N)/
Specimen
Base Speed
(rpm)/Direction
Time
(min:sec)
Carbimet paper
320- (P400) grit SiC
Water cooled
4 (18)
240
Comp.
Until
plane
Ultra-Pol cloth
9- m Metadi Supreme
diamond suspension
4 (18)
150
Comp.
4:00
Texmet 1000 pad
3- m Metadi Supreme
diamond suspension
5 (22)
120
Comp.
4:00
Microcloth pad
0.05- m Masterprep
alumina suspension
6 (27)
120
Comp.
3:00
75. Microstructure of Resiten G7 glass silicone laminate composite viewed with
Nomarski DIC. The magnification bars are 100 and 50 µm long, respectively
(left and right).
76. Microstructure of a graphite-fabric reinforced polysulfone composite
viewed with cross polarized light plus sensitive tint. The magnification
bar is 100 µm long.
77. Microstructure of a fiberglass-reinforced polymer I beam viewed with
Nomarski DIC. The magnification bar is 20 µm long.
78.
79. Extensive mechanical twinning was observed in high-purity, electron-
beam melted zirconium after hot working and cold drawing. Viewed in
polarized light. Magnification bar is 100 µm long.
80. Microstructure of wrought pure hafnium, with an as-polished specimen viewed in
polarized light plus sensitive tint, revealing an equiaxed alpha HCP grain
structure. A few mechanical twins can be seen at the surface (yellow arrows). The
magnification bar is 100 µm long.
Surface
Mount
81. Microstructure of a W – 27% Cu powder metallurgy composite material after hot
isostatic pressing. The specimen was etched with Klemm’s III for 20 seconds and
imaged with bright field. The magnification bar is 20 µm long.
82. Microstructure of Zn – 0.1% Ti – 0.1% Cu hot rolled to 6 mm thickness, in the
as-polished condition (left), using polarized light, revealing elongated HCP
grains containing mechanical twins. Some fine precipitates are present in the
grain boundaries but are not clearly revealed. For comparison, the structure on
the right is shown after etching with the Palmerton reagent and viewing with
polarized light plus sensitive tint). The magnification bars are 50 µm long.
83. Microstructure of Cd – 20% Bi in the as-cast condition, unetched, viewed with
polarized light (slightly off the crossed position) plus sensitive tint revealing
cadmium dendrites of various orientation. The interdendritic consituent is a
eutectic of Cd and Bi, but is too fine to resolve at this magnification. The
magnification bar is 200 µm long.
84. Microstructure of wrought 99.98% magnesium etched with the acetic-
picral reagent and viewed with crossed polarized light plus a sensitive
tint filter. The magnification bars are 200 and 100 µm long, left and
right, respectively.
85. Microstructure of as-cast Mg – 2.5% rare earth elements - -2.11% Zn –
0.64% Zr revealed using the acetic-picral reagent and viewed with polarized
light plus a sensitive tint filter. The magnification bars are 100 and 50 µm in
length, left and right, respectively. A few mechanical twins can be seen.
86. Surface Abrasive/Size Load,
lbs./(N)
Base Speed
(rpm)/Direction
Time
(min:sec)
CarbiMet
paper
320-grit (P400)
watercooled
6 (27) 240
Contra or Comp.
Until Plane
UltraPol Cloth
(psa)
9-µm MetaDi
Supreme
6 (27) 150
Contra
10:00
MicroCloth
pad
(psa)
0.05-µm
MasterPrep (1
part H2O2, 30%
conc, to 5 parts
alumina)
6 (27) 150
Contra
(head <100 rpm)
10:00
Do not use contra in step 3 if the head rotates >100 rpm, as the abrasive will be
splattered all over the room
87. Microstructure of CP Ti, ASTM F 67, Grade 2 (UNS R50400; specimen was in
the as-rolled condition) prepared using the three-step method and viewed with
polarized light to reveal the grain structure. Magnification bar is 100 µm long.
Note the mechanical twins in the grains (arrows).
88. Microstructure of CP Ti, ASTM F 67, Grade 2 (UNS R50400; specimen in the as-
rolled condition) prepared using the three-step method (previous slide) followed
by a 20 minute vibratory polish, and viewed with crossed polarized light to reveal
the grain structure. Original image at 100X. Magnification bar is 100 µm long.
Note the deformation twins (arrows).
89. Microstructure of a Ti- 0.2% Pd alloy (UNS R52400) prepared using the three-
step method and viewed with crossed polarized light to reveal an equiaxed alpha
grain structure. Magnification bar is 100 µm long. The area at the left shows
heavy deformation twinning (arrow) from sectioning (the cut edge is off the field of
view to the left).
90. Microstructure of as-cast Ti – 6% Al – 4% V prepared using the three-step
method, etched with modified Weck’s reagent, and viewed with polarized
light to reveal a coarse “basket-weave” alpha/beta matrix structure. The
boundaries of several former beta grains can be seen. Magnification bar is
200 µm long.
91. Microstructure of CP titanium containing SiC fibers prepared using the three-step
method for titanium. The structure was viewed with Nomarski DIC to reveal the
minor height differences. The magnification bar is 100 µm long.
