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The creep deformation and damage mechanism of compacted graphite cast iron (CGI) with varying pearlite contents were studied at 450 °C, 500 °C, and 550 °C, with accompanying stress ranges from 40 MPa to 150 MPa. The creep deformation of CGI alloys presents obvious when the temperature exceeds 450 °C. The creep rate exponentially decreases with pearlite contents and the creep mechanism changes from dislocation slip to grain boundary sliding. There are (Ⅰ) intergranular and transgranular cracks, (Ⅱ) interfacial debonding between graphite and matrix, and (Ⅲ) pearlite morphologic transforming in the microstructure of CGI during the creep test. (Ⅰ) and (Ⅱ) are mainly caused by the creep stress and temperature, and (Ⅲ) may be related to plastic deformation. These cracks can interact with each other and accelerate the failure and fracture of materials.

The tension-tension fatigue test of the compacted graphite cast iron (CGI) alloy was carried out by RDL100 universal testing at 500 °C and 550 °C, respectively. A tension-tension trapezoidal load is applied to the CGI specimen. Because of the time-dependent deformation at elevated temperatures, the stress–strain curve presents hysteresis loops, and the area of the hysteresis loop increases gradually with continuous cyclic loading and sustained loading times. Intergranular and transgranular cracks in the microstructure accelerate the CGI alloy fracture failure. The fatigue life is sensitive to the short loading time and decreases with the sustained loading time exponentially under the tension-tension fatigue condition. The short holding time has a great influence on the fatigue life of CGI. The fatigue behavior of CGI alloys and the influence of holding time on the fatigue life can be characterized by y = aexp(bx) (a and b are constants, can be fitted through the test data). In addition, the fatigue life of CGI alloy can be predicted by the ductility depletion method. But the equivalent stress amplitude needs to be modified to eliminate the effects of oxidation damage.

CoCrFeNiMn high-entropy alloy coatings were deposited on compacted graphite iron (CGI) by plasma transfer arc cladding to strengthen and improve the wear resistance (performance) of the surface. The effects of different heat treatment processes on the microstructure and mechanical properties of the CoCrFeNiMn coatings were investigated. Compared with the deposited coating, the single FCC phase in the heat-treated coatings was retained, the grain size of the columnar dendrites decreased, the spacing between the dendrites increased, and the Cr-rich precipitated phase in the grain boundary increased. The heat treatment process had a positive influence on the microhardness and wear resistance of the coatings. The microhardness of the coatings increased after heat treatment. After heat treatment at 660 °C for 90 min, the coating had the highest microhardness of 563 ± 6.9 HV0.2, and it had the best wear resistance. [ABSTRACT FROM AUTHOR]

Zeolite A (LTA)-coated Mn-doped perovskite quantum dot CsPb1–xMnxCl3@LTA (x = 0, 0.2, 0.4, 0.6, and 0.8) composites were fabricated by vapor deposition crystallization. LTA not only improved the water, light, and thermal stability of perovskite quantum dots but also limited the average size of perovskite quantum dots to less than 20 nm. Mn2+ doping improved the exciton lifetime of a perovskite quantum dot matrix. The photogenerated carriers generated by Mn2+ have a decay life of hundreds of microseconds, which effectively improves the photocatalytic efficiency. When x = 0.6, the total yield of CO and CH4 was 1443.25 μmol g–1 (1191.08 μmol g–1 of CO and 252.17 μmol g–1 of CH4). After 5 catalytic cycles, the yields of CO and CH4 remained at 53.77% and 62.27% of their original levels, respectively, indicating that CsPb1–xMnxCl3@LTA has excellent photocatalytic application prospects. [ABSTRACT FROM AUTHOR]

This article uses Sn as the metal flux and CaF2-CaO as the reference slag to experimentally measure the activity of CaO at T = 1773∼1873 K. The effects of different w(Al2O3) and temperature(T) on CaO activity were investigated. The results are as follows: when w(MgO) = 6%, R(w(CaO)/w(SiO2)) = 1.20, w(Al2O3) = 12%, 14%, 16% and 18%, with the increase of w(Al2O3), the activity and activity coefficient of CaO in slag gradually decrease; with the increase of temperature (T), the activity and activity coefficient of CaO in slag gradually increase; the activity coefficient of Ca in Sn decrease with increasing temperature. [ABSTRACT FROM AUTHOR]

The influence of TiB2 on the fatigue properties of Al-Si-Cu series alloys was discussed with the help of finite element simulation, and the feasibility of the spatial configuration distribution of the reinforcement to solve the problem of inversion of the strength and toughness of the particle reinforced metal matrix composites was verified, and the test efficiency was effectively improved. In this paper, the different content and distribution characteristics of TiB2 particles are introduced into the two-dimensional geometric model of Al-Si-Cu alloy materials through configuration design methods, and the influence of TiB2 particles on the stress amplitude and fatigue limit distribution of aluminum matrix composites under fatigue conditions is discussed with the help of computer finite element simulation technology. The results show that with the increase of TiB2 particle content, the stress amplitude first decreases and then increases. The minimum value at a particle content of 3% is reduced by 12% compared to no addition. The fatigue limit showed a trend of gradual increase, reaching a maximum at 5% TiB2 content, an increase of 55.9% year-on-year. With the increase of TiB2 agglomeration, the stress amplitude showed an overall trend of increase. The fatigue limit shows a trend of gradual reduction. Combined with the simulation results of fatigue stress amplitude and fatigue limit simulation, it is estimated that when the TiB2 particle content is 3%, the strength, toughness, fatigue strength, tensile strength and yield strength of the material reach the optimal state. This result provides some technical support for the design of TiB2 particle-reinforced aluminum matrix composites. [ABSTRACT FROM AUTHOR]