J. Am. Ceram. Soc., 94 [4] 969–972 (2011)
DOI: 10.1111/j.1551-2916.2010.04257.x
r 2011 The American Ceramic Society
ournal
J
Three-Dimensional Printing of Ti3SiC2-Based Ceramics
Beiya Nan, Xiaowei Yin,w Litong Zhang, and Laifei Cheng
National Key Laboratory of Thermostructure Composite Materials, Northwestern Polytechnical University, Xi’an,
Shaanxi 710072, China
In the present work, we explored the feasibility of fabricating
Ti3SiC2-based ceramics by a near-net-shape fabrication process
of three-dimensional printing (3D printing) combined with liquid
silicon infiltration (LSI). The porous ceramic preform was
fabricated by 3D printing TiC powder with dextrin as a binder.
The heat-treated preforms contained bimodal pore structure
with interagglomerate pores (dꢀ23 lm) and intraagglomerate
pores (dꢀ1 lm). Upon infiltration in Ar atmosphere at 16001–
17001C for 1 h, silicon melt infiltrated the pores and reacted with
TiC to yield Ti3SiC2, TiSi2, and SiC. The effects of silicon
content and infiltration temperature on the phase composition
of the Ti3SiC2-based composites were also studied. After LSI
at 17001C for 1 h, the composites with an initial TiC:Si mole
ratio of 3:1.2 attained a bending strength of 293 MPa, a
Vickers hardness of 7.2 GPa, and an electrical resistivity of
TiAl3–Al2O3 composites have been fabricated by a combination
process of 3D printing and aluminum melt reactive infiltra-
tion,13 which exhibited rising R-curve behavior with extensive
crack deflection along the (0001) lamellar sheets of Ti3AlC2.
In this work, for the first time, Ti3SiC2-based composite was
fabricated using a combination process of 3D printing and
liquid silicon infiltration (LSI). Effects of silicon content
and infiltration temperature on the microstructure and mechan-
ical properties of Ti3SiC2-based ceramic were studied.
II. Experimental Procedure
(1) Materials Preparation
A 90 wt% TiC powder (average particle size: 1.5 mm, 499%
purity, Longjin Co. Ltd., Shanghai, China) and 10 wt% dextrin
powder ((C6H10O5)n ꢁ xH2O, average particle size: 115 mm,
Hedong Hongyan, Tianjin, China) were mixed in distilled wa-
ter and ball milled for 12 h. The as-received slurry was dried
using a freeze drier (LGJ-18S, SongYuan HuaXing Co. Ltd.,
Beijing, China). After dry ball milling, the powder was passed
through a 60 mesh sieve. The green bodies were printed using
3D printer (Spectrum Z510, Z Corporation, Burlington, MA),
which were subsequently heat-treated in flowing argon at
14001C for 1 h in an Al2O3 tube furnace (Kejing Co. Ltd.,
Hefei, China). During the heat treatment process, the dextrin
was decomposed into pyrolysis carbon.
LSI was conducted in a high-temperature furnace (HT 1800
M-Plus, Linn High Therm GmbH, Eschenfelden, Bayern, Ger-
many) in an Ar atmosphere. The heat-treated preforms were in-
filtrated with silicon at 16001–17001C for 1 h, and then annealed
at 14001C for 2 h, and the initial TiC:Si mole ratio in the infil-
trated preforms was controlled to be 3:0.7, 3:0.9, and 3:1.2, re-
spectively. The heating and cooling rates were 10 and 21C/min,
respectively.
.
27.8 lX cm, respectively.
I. Introduction
HE TiSi2 possesses low density (4.04 g/cm3), moderate melt-
T
ing point (15401C), high elastic modulus (250 GPa),1 high
oxidation resistance (12001–13001C), and low electrical resist-
ivity (13–16 mO ꢁ cm),2 which receives considerable attention for
potential applications as a high-temperature material and elec-
tronic interconnections. However, low fracture toughness
(2–3 MPa ꢁ m1/2)1 and strength (170 MPa) greatly limit its poten-
tial applications.3 As a representative nanolaminated ternary car-
bide,4 Ti3SiC2 has high melting point, low density (4.53 g/cm3),
low hardness (Vickers hardness of 4 GPa),5 excellent thermal
shock resistance,6 high strength (bending strength 475 MPa),7
high fracture toughness (KIc 5 8–16 MPa ꢁ m1/2) depending on
the grain size,5,8 and low electrical resistivity (22 mOꢁ cm).4 Be-
cause Ti3SiC2 is relatively soft, hard materials such as TiC and
SiC have been combined to improve its hardness.7,9 Recently,
the thermal stability of Ti3SiC2–TiC–TiSi2 composite in vacuum
has been investigated.10 It was revealed that Ti3SiC2–TiC–TiSi2
composites were thermally stable at temperatures up to 13001C.
The combination of Ti3SiC2, SiC, TiC, and TiSi2 may produce a
composite with not only high mechanical properties and good
oxidation resistance but also low electrical resistivity.
(2) Characterization
The relative density and open porosity of the samples were mea-
sured by the Archimedes’ method. The pore size distribution
was measured using a Mercury Poremaster (Poremaster 33,
Quantachrome Instruments Co. Boynton Beach, FL). The elec-
trical resistivity was measured by the four-probe method using a
Quantum Design (Versa Lab, San Diego, CA). The microstruc-
ture of the fractured surfaces was observed by scanning electron
microscopy (SEM, S-2700, Hitachi, Tokyo, Japan), and the el-
emental analysis was conducted by energy-dispersive spectros-
copy (EDS). Hardness was measured using a Vickers hardness
machine (HBV-30A, Huayin Co. Ltd., Laizhou, China) using
100 N load with a dwell time of 15 s. The samples with a di-
mension of 3 mm ꢂ 4 mm ꢂ 35 mm were used to test the three-
point bending strength using an Instron universal testing ma-
chine (CMT 4304, Sans Materials Testing Co. Ltd., Shenzhen,
China). The span was 30 mm and the cross-head speed was
0.5 mm/min. Infiltrated samples were also crushed into a powder
and analyzed by X-ray diffractometry (XRD, Rigaku D/max-
2400, Tokyo, Japan) with CuKa radiation at 40 kV and 100 mA.
Three-dimensional printing (3D printing) is a promising
additive manufacturing technology, which can create complex-
shape ceramic parts that cannot be produced by traditional ap-
proaches.11,12 While 3D printing may produce porous preforms
with a high degree of freedom in geometry and shape, capillary-
driven infiltration of the metal melt followed by a subsequent
reaction in the composite material may result in a dense micro-
structure of the component. Nanolaminated Ti3AlC2 toughened
N. Travitzky—contributing editor
Manuscript No. 28670. Received September 26, 2010; approved October 14, 2010.
This work was financially supported by the Natural Science Foundation of China
(Grant: 50802074) and the 111 Project (B08040).
969