Showing papers by "Tianshu Zhang published in 2015"
TL;DR: In this article, an electron-doped perovskite Ca 1− x Bi x MnO 3 (x ǫ=0, 002, 003, 004, 006 and 010) was prepared by a conventional solid-state reaction method.
57 citations
TL;DR: The phase composition, microstructural and thermoelectric properties of n-type Sr 1−1.5 x Y x TiO 3−δ (0.88 Y 0.08 ) have been investigated over the temperature range of 50°C to 680°C as mentioned in this paper.
31 citations
01 Jan 2015
TL;DR: In this paper, it was shown that some non cubic-structured materials can also be processed into transparent ceramics, such as tetragonal ferroelectric and hexagonal alumina.
Abstract: Various transparent ceramics have been fabricated by different processing techniques. Previously, it was accepted that, to be transparent ceramics, materials should have an isotropic lattice structure, i.e., cubic structure. However, as demonstrated in this chapter, some non cubic-structured materials can also be processed into transparent ceramics, such as tetragonal ferroelectric ceramics and hexagonal alumina ceramics. In addition, transparent ceramics have been derived from glasses through thermal annealing. This chapter is aimed to summarize transparent ceramics that have been reported in the open literature.
18 citations
01 Jan 2015
TL;DR: A wide range of methods have been used to synthesize ceramic powders, with different compositions as discussed by the authors, but some of these methods have not been employed in the fabrication of transparent ceramics.
Abstract: A wide range of methods have been used to synthesize ceramic powders, with different compositions. Although most of these methods are applicable to transparent ceramic power synthesis, some of them have not been employed in the fabrication of transparent ceramics. Solid-state reaction is still the key method, while wet-chemical routes are increasingly used, whereas gas-phase reactions are only limited to nonoxide ceramics. For large-scale applications, cost-effectiveness, environmental friendliness, and less energy consumption are all very important considerations, when selecting synthetic methods.
17 citations
TL;DR: In this paper, the thermoelectric properties in Sn and Lu co-doped In 2 O 3 were investigated by using a co-precipitation method followed by spark plasma sintering (SPS) process.
12 citations
01 Jan 2015
TL;DR: In this article, the quality of a starting powder is evaluated by microstructure monitoring or control of the final ceramics with desired properties and performances, and the understanding of powder quality is important for two reasons.
Abstract: Once a ceramic powder is synthesized, there should be some parameters or data to demonstrate its properties or quality. The understanding of powder quality is important for two reasons: (i) quality control of the starting powders and (ii) microstructure monitoring or controlling of the final ceramics with desired properties and performances.
5 citations
01 Jan 2015
TL;DR: In this paper, the fundamental issues of conventional sintering technologies are discussed, including the driving forces of sinterding, the mechanisms of densification, controlling factors, such as particle size of precursor powders, sinter temperature, time duration and applied pressure, electrical current, and so on.
Abstract: It is well known that, to produce ceramics, green bodies must be sintered at a certain high temperature for a given time duration to develop required microstructure and thus desired properties. In particular, transparent ceramics must be fully dense to achieve maximum optical transmittance. Sintering process is governed by a number of parameters, which can be used to build up interrelationships among processing, microstructure, properties, and performance. Sintering behavior and microstructure development have been extensively studied. Qualitative understandings include driving forces of sintering, the mechanisms of densification, controlling factors, such as particle size of precursor powders, sintering temperature, time duration and applied pressure, electrical current, and so on. This chapter serves to cover the fundamental issues of the conventional sintering technologies.
3 citations
23 Dec 2015
TL;DR: In this article, the latest progress in processing, materials, and applications of transparent ceramics is summarized, and the two key requirements for high purity and high density are high-purity precursor powders, while to achieve high density, special technologies have to be used.
Abstract: Transparent ceramics can be used as laser hosts, infrared (IR) windows/domes, lamp envelopes, and transparent armors. The two key requirements for transparent ceramics are high purity and high density. To ensure high purity, it is necessary to use high-purity precursor powders, while to achieve high-density, special technologies have to be used, such as high-pressure (HP) sintering, high isostatic pressure (HIP) sintering, vacuum sintering, and spark plasma sintering (SPS). In this article, the latest progress in processing, materials, and applications of transparent ceramics is summarized.
Keywords:
transparent ceramics;
high-pressure (HP) sintering;
high isostatic pressure (HIP) sintering;
spark plasma sintering (SPS);
densification;
microstructure;
optical property;
IR transmittance;
laser;
armor;
IR window/dome;
nanoceramics
2 citations
01 Jan 2015
TL;DR: The properties of a ceramics are determined by its chemical composition intrinsically and microstructure extrinsically as mentioned in this paper, which reflects its grain size and morphology, grain size distribution, porosity, pore size and distribution, type and quality of grain boundaries, as well as the nature and distribution of second-phases.
Abstract: The properties of a ceramics are determined by its chemical composition intrinsically and microstructure extrinsically. For ceramics with a given composition, microstructure means the overall feature, which reflects its grain size and morphology, grain size distribution, porosity, pore size and distribution, type and quality of grain boundaries, as well as the nature and distribution of second-phases, and so on. For most applications, especially optical transparency, microstructural control means to achieve full densification, narrow distribution of grain size, least contamination, and so on.
1 citations
01 Jan 2015
TL;DR: There are various sintering techniques that can be used to fabricate transparent ceramics as mentioned in this paper, and different methods can be combined to offer higher Sintering efficiency, depending on materials.
Abstract: There are various sintering techniques that can be used to fabricate transparent ceramics. Conventional sintering techniques include vacuum sintering, hot pressing (HP), and hot isostatic pressing (HIP), while spark plasma sintering (SPS) is more popular than microwave sintering in the new sintering technique category. Every method has its own advantages and disadvantages. Different methods can be combined to offer higher sintering efficiency. The selection of sintering technique is also dependent on materials.
1 citations
06 Feb 2015
01 Jan 2015
TL;DR: In this article, the principles, analysis and simulations of SPS and microwave sintering technologies are described, which could be useful to the processing of transparent ceramics, and the principles and analysis of these technologies are discussed.
Abstract: Besides the conventional sintering techniques discussed in the previous chapter, various new sintering methods, such as microwave (MW) sintering, spark plasma sintering (SPS), and flash sintering, have been developed for ceramic processing. These methods have also been used to fabricate transparent ceramics. This chapter is used to describe the principles, analysis and simulations of SPS and microwave sintering technologies, which could be useful to processing of transparent ceramics.