Photopolymerization-based additive manufacturing of ceramics:A systematic review

Conversion of inorganic-organic frameworks (ceramic precursors and ceramic-polymer mixtures) into solid mass ceramic structures based on photopolymerization process is currently receiving plentiful attention in the field of additive manufacturing (3D printing).Various techniques(e.g.,stereolithography,digital light processing,and two-photon polymerization) that are compatible with this strategy have so far been widely investigated.This is due to their cost-viability,flexibility,and ability to design and manufacture complex geometric structures.Different platforms related to these techniques have been developed too,in order to meet up with modem technology demand.Most relevant to this review are the challenges faced by the researchers in using these 3D printing techniques for the fabrication of ceramic structures.These challenges often range from shape shrinkage,mass loss,poor densification,cracking,weak mechanical performance to undesirable surface roughness of the final ceramic structures.This is due to the brittle nature of ceramic materials.Based on the summary and discussion on the current progress of material-technique correlation available,here we show the significance of material composition and printing processes in addressing these challenges.The use of appropriate solid loading,solvent,and preceramic polymers in forming slurries is suggested as steps in the right direction.Techniques are indicated as another factor playing vital roles and their selection and development are suggested as plausible ways to remove these barriers.

Enhanced cathodic activity by tantalum inclusion at B-site of La_(0.6)Sr_(0.4)Co_(0.4)Fe_(0.6)O_(3)based on structural property tailored via camphor-assisted solid-state reaction

Lanthanum strontium cobalt ferrite(LSCF)is an appreciable cathode material for solid oxide fuel cells(SOFCs),and it has been widely investigated,owing to its excellent thermal and chemical stability.However,its poor oxygen reduction reaction(ORR)activity,particularly at a temperature of≤800℃,causes setbacks in achieving a peak power density of>1.0 W·cm^(-2),limiting its application in the commercialization of SOFCs.To improve the ORR of LSCF,doping strategies have been found useful.Herein,the porous tantalum-doped LSCF materials(La_(0.6)Sr_(0.4)Co_(0.4)Fe_(0.5)7Ta_(0.03)O_(3)(LSCFT-0),La_(0.6)Sr_(0.4)Co_(0.4)Fe_(0.5)4Ta0.06O_(3),and La_(0.6)Sr_(0.4)Co_(0.4)Fe_(0.5)Ta0.1O_(3))are prepared via camphor-assisted solid-state reaction(CSSR).The LSCFT-0 material exhibits promising ORR with area-specific resistance(ASR)of 1.260,_(0.5)80,0.260,0.100,and 0.06Ω·cm^(2)at 600,650,700,750,and 800℃,respectively.The performance is about 2 times higher than that of undoped La_(0.6)Sr_(0.4)Co_(0.4)Fe_(0.6)O_(3)with the ASR of 2.515,1.191,_(0.5)96,0.320,and 0.181Ω·cm^(2)from the lowest to the highest temperature.Through material characterization,it was found that the incorporated Ta occupied the B-site of the material,leading to the enhancement of the ORR activity.With the use of LSCFT-0 as the cathode material for anode-supported single-cell,the power density of>1.0 W·cm^(-2)was obtained at a temperature<800℃.The results indicate that the CSSR-derived LSCFT is a promising cathode material for SOFCs.