Sökning: "Zhijian Shen"

Visar resultat 1 - 5 av 12 avhandlingar innehållade orden Zhijian Shen.

1. 1. Synthesis and Characterization of Nitrogen-rich Calcium α-Sialon Ceramics

   Författare :Yanbing Cai; Saeid Esmaeilzadeh; Zhijian Shen; Elis Carlström; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nitrogen-rich; SiAlON; Sintering; Microstructure; Properties; Inorganic chemistry; Oorganisk kemi; oorganisk kemi; Inorganic Chemistry;

   Sammanfattning : In this thesis, a synthesis concept has been developed, which uses nitrogen-rich liquid phases for sintering of Ca-α-sialon ceramics. First, keeping the Si/Al ratios constant, the effects of N/O ratio on the properties and microstructure were investigated through a liquid phase sintering process. LÄS MER

3. 2. Spark plasma sintering and deformation behaviour of Titanium and Titanium/TiB2Spark plasma sintering and deformation behaviour of Titanium and Titanium/TiB2 composites

   Författare :Mirva Eriksson; Zhijian Shen; Guocai Chai; Stockholms universitet; []
   Nyckelord :materialvetenskap; Materials Science;

   Sammanfattning : Titanium has been used as a model substance to study how it behaves in a SPS apparatus when heating rate and/or pressure were varied during the sintering and deformation process. The sintering and deformation of Ti in SPS were compared with that occurring in the conventional hot pressing (HP) in order to reveal if there are any positive effects added by the use of SPS. LÄS MER

4. 3. Spark Plasma Sintering Enhancing Grain Sliding, Deformation and Grain Size Control : Studies of the Systems Ti, Ti/TiB2, Na0.5 K0.5 NbO3, and Hydroxyapatite

   Författare :Mirva Eriksson; Zhijian Shen; Takashi Goto; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Spark plasma sintering; plastic deformation; grain growth; titanium; TiB2; hydroxyapatite; Na0.5K0.5NbO3; ferroelectric; transparent; Materials chemistry; Materialkemi; Materials Chemistry; materialkemi;

   Sammanfattning : The unique features of the Spark plasma sintering (SPS) were used to investigate the sintering and deformation behaviour of titanium and titanium–titanium diboride composites, and to control the sintering and grain growth of ferroelectric Na0.5K0.5NbO3 (NKN) and of hydroxyapatite (HAp). LÄS MER

5. 4. The synergistic role of hierarchical macro- and mesoporous implant surface and microscopic view of enhanced osseointegration

   Författare :Guang Han; Zhijian Shen; Anders Palmqvist; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Porosity; cell adhesion; cell proliferation; surface topography; implant; bone-implant interface; argon ion beam polishing; osteogenesis; osseointegration; Materials Chemistry; materialkemi;

   Sammanfattning : The trend for designing of a titanium implant explored using different chemical compositions and crystallinity materials until people realized that the implant surface character was another important factor affecting the rate and extent of osseointegartion. Titanium received a macroporous titania surface layer by anodization, which contains open pores with average pore diameter around 5μm. LÄS MER

7. 5. Grain growth by Ordered Coalescence of crystallites in Ceramics : Grain Growth Mechanisms, Microstructure Evolution and Sintering

   Författare :Jianfeng Hu; Zhijian James Shen; Jekabs Grins; Viveka Alfredsson; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Inorganic Chemistry; oorganisk kemi;

   Sammanfattning : Grain growth and densification process play the two most crucial roles on the microstructure evolution and the achieved performances during sintering of ceramics. In this thesis, the grain growth of SrTiO3, BaTiO3-SrTiO3 solid solutions and Si3N4 ceramics during spark plasma sintering (SPS) were investigated by electron microscopy. LÄS MER