•The porous Ni–Cu alloy with different open porosity and abundant interconnected pores were fabricated by powder metallurgy.•The sintered porous Ni–Cu alloy exhibits superior corrosion resistance to porous Ni in aqueous hydrofluoric acid.•The porosity has little influence on the corrosion resistance of the sintered porous Ni–Cu alloy in hydrofluoric acid solution.The porous Ni–Cu alloy with different porosity was fabricated through mixed elemental powders reaction synthesis by step sintering in vacuum furnace. The corrosion resistance and corrosion mechanism of the sintered porous Ni–Cu alloy in hydrofluoric acid (HF) were investigated by the immersion test, the potentiodynamic polarization and the electrochemical impedance spectroscopy (EIS) techniques. Results show that the sintered porous Ni–Cu alloy exhibits good corrosion resistance in hydrofluoric acid solution, compared with porous Ni. The corrosion rate of the sintered porous Ni–Cu is dependent upon the concentration of hydrofluoric acid solution, no passive phenomenon is found in potentiodynamic polarization curve in any concentration. Double capacitive loops for the porous Ni–Cu alloy in EIS results show that the corrosion process is controlled by electrochemical reaction. Moreover, the porosity has little influence on the corrosion resistance of the sintered porous Ni–Cu alloy in hydrofluoric acid solution, which is most likely due to the homogenous pore structure and chemical composition of the material, as well as the chemical stability of the bulk alloy itself.

In this paper, micrometer-sized porous Ti3SiC2 metal ceramic was fabricated through a reactive synthesis method using titanium hydride, silicon and graphite elemental powders. The factors including raw powders, pressing pressure, sintering procedure affecting the purity and the pore property of porous Ti3SiC2 were systematically studied. The results indicate that the purity, pore property including maximum pore size and porosity can be effectively controlled by adjusting the synthesis parameters.

Pore structure control methods for porous FeAl intermetallics were studied in this paper based on pore formation mechanism. A large range of pore structure parameters can be obtained through fabrication parameter adjustment in porous FeAl preparation procedure. Open porosity and maximum pore size of porous FeAl have a direct proportional relationship to the powder size of raw materials and an inversely proportional relationship to the pressing pressure. The relationship between maximum pore size (dm) and raw material powder size (dp) can be determined as dm=0.40dPdm=0.40dP. Open porosity and maximum pore size decrease with increasing holding time at solid diffusion reactive procedure. The quantitative relationship between open porosity (θ) and holding time (t  ) at 600 °C is θ=49.7−0.1t(60≤t≤240); the quantitative relationship between maximum pore size (dm) and holding time (t  ) at 600 °C is dm=20.3−0.065t(60≤t≤240).Highlights► The relationship between maximum pore size (dm) and raw material powders size (dp) of porous FeAl in our experimental condition can be determined as dm = 0.40dp. ► Open porosity and maximum pore size decrease with increasing holding time at solid diffusion reactive process. ► The quantitative relationship between open porosity(θ) and holding time(t) at 600 °C is θ = 49.7 − 0.1t (60 ≤ t ≤ 240). ► The quantitative relationship between maximum pore size (dm) and holding time (t) at 600 °C is dm = 20.3 − 0.065t (60 ≤ t ≤ 240).

Three new benzo[1,2-b:4,5-b′]difuran-based donor–acceptor conjugated polymers, namely poly{4,8-bis(2′-ethylhexyloxy)benzo[1,2-b;3,4-b′]difuran-alt-5,5-(4′,7′-di-2-thienyl-5′,6′-dioctyloxy-2′,1′,3′-benzothiadiazole)}(PBDFDODTBT), poly{4,8-bis(2′-ethylhexyloxy)benzo[1,2-b;3,4-b′]difuran-alt-5,5-(4′,7′-di-2-thienyl-2-octyl-2′,1′,3′-benzotriazole)}(PBDFDTBTz), poly{4,8-bis(2′- ethylhexyloxy)benzo[1,2-b;3,4-b′]difuran-alt-5,5-(4′,7′-di-2-thienyl-5′,6′-dioctyloxy-benzo[c][1,2,5]oxadiazole)}(PBDFDTBO), were synthesized by Stille coupling polymerization reactions. All of the polymers were found to be soluble in common organic solvents such as chloroform, tetrahydrofuran and chlorobenzene with excellent film forming properties. Their structures were verified by 1H NMR and elemental analysis, the molecular weights were determined by gel permeation chromatography (GPC) and the thermal properties were investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The polymer films exhibited broad absorption bands. The hole mobility of PBDFDODTBT:PC71BM (1:2, w/w) blend reached up to 6.7 × 10–2 cm2·V–1·s–1 by the space-charge-limited current (SCLC) method. Preliminary photovoltaic cells based on the device structure of ITO/PEDOT:PSS/PBDFDODTBT:PC71BM(1:2, w/w)/Ca/Al showed an open-circuit voltage of 0.69 V, a power conversion efficiency of 4.5% and a short circuit current of 9.87 mA·cm–2.