Semi-solid tin bronze blanks was prepared by cold rolling-isothermal treatment SIMA method (CRITSIMA method), and then tin bronze bushing parts were extruded. The effect of isothermal treatment time on the microstructure and mechanical properties of thixotropic tin bronze bushing parts is investigated. The results show that with the increase of isothermal treatment time, the average grain size gradually increased, the coarsening rate of solid grain is 296 μm³/s, the shape factor first increased and then decreased, the Brinell hardness first increased and then decreased, the tensile strength gradually decreased, and the elongation first increased and then decreased. The microstructure and comprehensive properties of the tin bronze bushing are the best when kept at 910℃ for 15 min. The shape factor is 0.74, the average grain size is 63.56 μm, the tensile strength is 368 MPa, the elongation is 4.5%, and the Brinell hardness is 126 HBW.

The third generation DD33 single crystal superalloy was subjected to standard heat treatment and hot isostatic pressing respectively, and then to different post-solution and -aging treatments. Hereafter, the effect of hot isostatic pressing and heat treatment on the microstructure and durability of the alloy were investigated by means of high-temperature endurance tests at 850℃/650 MPa and 1100℃/170 MPa, as well as metallographic microscope (OM), scanning electron microscope (SEM) and X-ray three-dimensional imaging (XCT). The results show that after proper hot isostatic pressing and subsequent heat treatment, the as-cast DD33 single crystal superalloys present more or less the same microstructure of (γ' phase size, volume fraction and cubic degree) as those subjected to standard heat treatment. Compared with the standard heat treated alloy, the volume fraction and size of the micropores of the alloy decreased significantly after hot isostatic pressing, from 0.0190% to 0.0005%, and the maximum equivalent diameter of the micropores decreased from 36.9 μm to 14.2 μm. The durable life of the alloy subjected to hot isostatic pressing was significantly prolonged when testing by 850℃/650 MPa and 1100℃/170 MPa. These results show that proper hot isostatic pressing and heat treatment can eliminate the micro voids, therewith, improve the durability of the alloy.

The phase transition temperature of Ac1 and Ac3 of 09MnNiDR steel for typical vessel was measured by thermal expansion method, and based on this two new quenching processes were designed. The microstructure, texture and low temperature impact properties of the samples at 1/2 thickness of the plate were investigaed by means of SEM, EBSD and Charpy impact tester. The results show that: Ac1 and Ac3 of 09MnNiDR steel is 692.9℃ and 883.1℃ respectively; compared with the "quasi sub temperature quenching + tempering" or "quasi sub temperature quenching + sub temperature quenching + tempering" heat treatment process, the "pre quenching + quasi sub temperature quenching + tempering" heat treatment could improve the low temperature impact property of the samples at 1/2 thickness of 09MnNiDR steel plate greatly, and one reason of the impact property improvement is grain refinement, another reason is the random distribution of texture.

Superplastic tensile tests of 7B04 Al-alloy plates with average grain sizes of 10 and 20 μm were carried out at strain rate of 3×10^-4 s^-1 at 530℃ and with various desired deformation degrees. The results show that, as the deformation degree increases, the evolution of cavity morphology of the alloys follows the following order: cavity nucleation → spherical cavity dispersion → nonspherical cavity elongation along the stretching direction → cavity coalescence along the stretching direction → large-size cavity coalescence in the non-stretching direction. In the deformation stage before tensile fracture, there were polymeric cavities larger than 260 μm in size. At the initial stage of coalescence, the cavities aggregate along the tensile direction did not lead to fracture immediately. Large-size cavities coalesce along the non-tensile direction, which is the basis for judging the instability of materials. According to the experimental data, the cavity growth equation was established and the Cavity Growth Mechanism Map (CGMM) was plotted, including equations related with the nucleation, diffusion growth, plastic growth and aggregation growth of cavities, based on the CGMM the cavity morphology and material instability can be judged. According to the evolution of microstructure a physical model of cavity diffusion and plastic growth was established, based on which the energy dissipation required by cavity evolution during superplastic deformation can be calculated and the energy dissipation diagram can be drawn.

The recrystallized SiC was prepared via argon atmosphere sintering with SiC of different particle sizes as raw material and submicron Al₂O₃ as additives, and its phase composition, microstructure, pore size distribution and compression resistance were characterized by means of universal testing machine, X-ray diffractometer, plasma spectrometer, scanning electron microscope and mercury porosimeter. The results show that due to the presence of submicron Al₂O₃, the sintering process of the recrystallized SiC can be differentiated into two stages: liquid phase sintering and recrystallization sintering. The highly active sub-micron Al₂O₃ promotes the formation of liquid phase during liquid phase sintering stage, therewith, the mass transfer mode of SiC changed from diffusion to viscous flow. During recrystallization sintering stage, the mass transfer of SiC at high temperature is dominated by evaporation and condensation, forming Al-containing gas phase and solid solution with SiC, which promotes the crystallographic transformation of the recrystallized SiC, i.e., from 6H-SiC to 4H-SiC. After introducing submicron Al₂O₃, the pore size distribution of recrystallized SiC material changes from unimodal to multimodal, of which, the characteristic peak of small size pores correspond to the course of recrystallization and sintering, whereas, the characteristic peak of large pore size presents the course of liquid phase sintering. At the same time, the SiC grains grow and develop much perfectly with the prolonging of holding time, correspondingly, the SiC grains change from irregular granular to more regular hexagonal structure. However, the decrease of bulk density, the inhomogeneity of SiC grain size and the multi-peak distribution of pore size, so that decrease the compressive strength of the SiC product.

The superhydrophobic yellow coating was prepared by mixing titanium chromium brown powder (TCB), rutile titanium dioxide (TiO₂), hydrophobic nano silica (SiO₂) with polydimethylsiloxane (PDMS) solution and brush coating by one step. The surface wettability, hydrophobic stability, ultraviolet light aging resistance, self-cleaning performance and near-infrared reflection performance of the coating were systematically investigated. The results show that the water contact angle (CA) and roll angle (SA) of the coating are 155.2° and 5.4°, respectively; the coating retains excellent hydrophobicity after sandpaper wear at a distance of 2 m by 1.0 kPa and water impact at a distance of 5 L, meanwhile its adhesion and hardness reach grade 2 and 6B, respectively; the coating surface presents superhydrophobic effect and have chemical stability in solutions of different pH; The coating surface still retains strong hydrophobicity after ultraviolet light irradiation for 240 h, indicating that it has UV aging resistance; the coating surface has excellent self-cleaning performance, and the pollutants are easily carried away by water droplets; the near-infrared reflectance and solar reflectance of the coating are 0.858 and 0.672, respectively. The coating has obvious cooling effect on the ordinary cement board, and still maintains a high reflectance after outdoor exposure and water impact.

Coatings of Cr and CrAl (14% Al, mass fraction) were prepared on Zr-4 alloy substrate by magnetron sputtering method. The oxidation resistance of Cr and CrAl coatings in high temperature steam (simulated the situation of LOCA accident) was investigated by means of steam oxidation test at 1200℃ for 1 h, scanning electron microscope (SEM), energy dispersive spectroscope (EDS) and X-ray diffractometer (XRD). The results show that the thickness of oxide scaled formed on the uncoated Zr-4 alloy is about 100 μm after steam oxidation at 1200℃/1 h, while a dense Cr₂O₃ scale of about 4 μm in thickness formed on the Cr coating surface, and the oxidation rate decreases significantly. The oxidation rate of CrAl coating is even lower than that of Cr coating due to the formation of a dense scale of mixed oxides Cr₂O₃ and Al₂O₃ of about 0.8 μm in thickness. It can be concluded that Cr and CrAl coatings prepared by magnetron sputtering on Zr-4 alloy have good resistance to high temperature steam oxidation at 1200℃. The thickness of the oxide scale formed on the surface of Cr coating is about 1/25 of that on Zr-4 alloy, and the thickness of the oxide scale on the surface of CrAl coating is less than 1/100 of that on Zr-4 alloy.

Referring to the simulation results, the effects of pulse current with different parameters on the solidification structure and properties of directionally solidified Ti-45.5Al-4Cr-2.5Nb (%, atom fraction) alloy were investigated. The results show that when the pulse current frequency is 200 Hz, due to the skin effect of current and Joule heat effect of current the surface current of melt is biased and the lateral heat dissipation decreases, the average deviation angle of dendrite decreases, and the elongation increases with the decrease of deviation angle. When the density of pulse current is small, the average width of grains decreases with the increase of current density due to Joule heat effect of current and electromagnetic stirring which promote the remelting or breaking of dendrites. However, when the current density reaches a certain value, the melting zone grows up and the temperature gradient decreases. On the contrary, the average width of grains increases and the tensile strength of TiAl alloy first increases with the increase of current density, and then decreases; Compared with the master alloy ingot, the tensile strength and elongation of TiAl alloy increased by 70.7% and 129.5% respectively.

Laminated plates of carbon fiber reinforce plastic (CFRP) with different stacking sequences, namely [45/-45]_4s, [0/90]_4s and [0/45/-45/90]_2s were produced via autoclave.They were glue-jointed with Al-plate to prepare single-lap joint samples at room temperature. The single-lap joint performance of the prepared samples was assessed by means of universal testing machine, digital image correlation (DIC) and scanning electron microscope (SEM) in terms of load-displacement curves, strain field distribution and fracture appearance of adhesive joints. On this basis, the mechanical properties of CFRP-Al single-lap joints were analyzed, the influence of different stacking sequences on the bonding performance of CFRP-Al single-lap joints, while the failure mechanism of adhesive joints were revealed. The results show that during the tensile process, the sample with [45/-45]_4s presents a plastic deformation stage and its tensile displacement is the largest; while the tensile displacements of samples with [0/45/-45/90]_2s and [0/90]_4s are less, and they present brittle fracture. In general, the ultimate load of the sample and the number of fiber bundles fracture increase for samples in the following order, namely samples with [45/-45]_4s, [0/45/-45/90]_2s and [0/90]_4s, but their interlaminar shear force, the strain field concentration degree and the delamination damage degree gradually decrease.