Abstract: Mg65Cu20Y10Ag5 Amorphous/ nano ZrO2 composites alloy powder were fabricated
through the combination method of melt spinning and mechanical alloying (MA). The melt spun
amorphous matrix ribbons are ground into powders and mixed with 3 vol.% ZrO2 nano particles in
the planetary mill. After then formed by hot pressing in Ar atmosphere under the pressure of 700
MPa at the temperature of soft point which measured by TMA (Thermal mechanical Analysis). The
hot-pressed bulk composite specimens are compression tested at different temperature within the
supercooled temperature region. The flow stress was found decrease with increasing temperature
dramatically when the temperature exceeds the middle temperature of supercooled region. The
specimens after compression test were examined by X-ray diffractometry and SEM to investigate
its crystallinity and fracture mechanism.
Abstract: Hybridization is a promising method for core/shell particles by a mechanical shock process
involving dry blending and dry impact blending. In this paper, hybridization was used to prepare
TiB2/Ni ceramics/metal and TiB2/Al2O3 ceramics/ceramics core/shell particles. The mechanism of
the formation and the features of the core/shell particles were analyzed. The nano- Al2O3 particles
can be coated on the surface of micron TiB2 particles directly by hybridization, The sub-micron
Al2O3 particles can be coated on the surface of micron TiB2 particles, only with the introducing of
PE-wax as transition layer. The mechanical properties of cermet sintered from TiB2/Ni core/shell
ceramics/metal particles were compared with that from TiB2/Ni blended particles.
Abstract: Friction stir processing (FSP) has been applied to fabricate 10~20 vol% nano-sized ZrO2
and 5~10 vol% nano-sized SiO2 particles into an Mg-AZ31 alloy to form bulk composites under
the FSP parameters of advancing speed of 800 rpm and pin rotation of 45 min/min. The
microstructures and mechanical properties of the resulting composites were investigated. The
clustering size of nano-ZrO2 and nano-SiO2 particles, measuring average ~200 nm was relatively
uniformly dispersed, and the average grain size of the both Mg alloy of the composites varied
within 1.0~2.0 μm after four FSP passes. No evident interfacial product between ZrO2 particles and
Mg matrix was found during the FSP mixing in AZ31-Mg/ZrO2. However, significant chemical
reactions at the AZ31-Mg/SiO2 interface occurred to form the Mg2Si phase. The mechanical
responses of the nano-composites in terms of hardness and tensile properties are examined and
Abstract: Nano-scale 8mol% titania doped yttria stabilized zirconia (8TiYSZ) powders were
prepared by coprecipitation combined with azeotropic distillation process. Powder X-ray
diffraction, BET method and TEM were performed to characterize the powder properties. The
relative density of 8TiYSZ sample sintered by spark plasma sintering technique at 1150°C for 3min
reached 99%. The electrical conductivity of sintered pellet was much higher than the reported one.
Abstract: Bond strength of metal-glass bilayer laminate was determined via a simple testing
approach using cross-bonded sample and a special fixture. Tensile and shear strength in the
interface for glass-metal composite were obtained by this way. It is demonstrated that the strength
can be accurately determined when it is lower than the glue strength but it is invalid if the strength
is higher than the glue strength. The specimen preparation and testing principle is introduced for
determining the interface bonding strength of coatings.
Abstract: The coefficients of thermal expansion (CTEs) of the 20 vol% SiCp/Al composites
fabricated by powder metallurgy process were measured and examined from room temperature to
450°C The SiC particles are in three nominal sizes 5μm, 20μm and 56μm. The CTEs of the SiCp/Al
composites were shown to be apparently dependent on the particle size. That the larger particle size,
the higher CTEs of the composites, is thought to be due to the difference in original thermal residual
stresses and matrix plasticity during thermal loading. The thermal conductivity of the composites
also increases with particle size increasing.
Abstract: In the present work, Al2O3 was coated on the quartz fiber by the sol-gel method to
improve the high temperature mechanical properties of the quartz fiber/methyl silicon resin
composites. The X-ray diffraction results showed that the crystalline property of the Al2O3 coating
increased with the processing temperature. Before 500oC treated, the Al2O3 coated fiber reinforced
composites have lower flexural strength than the commercial fiber reinforced one. While after
500oC treated, the flexural strength of Al2O3 coated fiber reinforced composites was higher than the
uncoated reinforced one. And the flexural strength for the 400oC treated Al2O3 coated fiber
reinforced composites was higher than that of the 600oC treated one. The mechanism of the crack
propagation in the purchased and Al2O3 coated fiber reinforced composites was also studied
through scanning electronic microscopy (SEM).
Abstract: ZrB2/SiC ceramic composites reinforced by nano-SiC whiskers and SiC particles have
been prepared by hot-pressing at 1950°C for 1hr under 20 MPa pressure in flow argon atmosphere.
Effects of SiC addition on microstructure, mechanical properties and thermal ablation/oxidation
behavior of ZrB2/SiC composites were investigated. The results showed that the addition of SiC
effectively improved the densification of ZrB2/SiC composites and almost full dense ZrB2/SiC
composites were obtained when the amount of SiC increased up to 20 vol%. Flexural strength and
fracture toughness of the ZrB2/SiC composites were also enhanced; the maximum strength and
toughness reached 600 MPa and 8.81 MPa·m1/2 at SiC additions of 20 vol % and 30 vol%,
respectively. The composites possessed good resistance to flame ablation and could keep the whole
shape without distinct peeling or cracking after flame ablation by oxyacetylene flame for 3 mins.
The more SiC added, the better resistance to flame ablation the composites displayed.
Abstract: Friction and wear properties of aluminum matrix composites are studied, including brake
speed, brake pressure, and surface temperature etc. A conclusion can be drawn that SiC particle
reinforced aluminum matrix composites are of stable friction coefficient, high thermal conductivity,
and excellent wear-resistance. Hubs of motorcycle with brake rings of Al/SiC composites were
manufactured and exhibited an excellent braking performance.
Abstract: The (AlN+Mg2Si)/Mg metal matrix composite was successfully fabricated by adding Si3N4
into Mg-Al alloy. The formation mechanisms of AlN and Mg2Si were analyzed; the effects of
synthesizing temperature and holding time were investigated as well.