Sökning: "Zhijian james Shen"

Hittade 3 avhandlingar innehållade orden Zhijian james Shen.

1. 1. 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

3. 2. Additive metallurgy - Thermal influences on structure and properties of stainless steel 316L

   Författare :Jon Olsén; Zhijian James Shen; Dongdong Gu; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Additive manufacturing; Selective laser melting; Electron beam melting; Hot isostatic pressing; Stainless steel; Microstructural heterogeneity; Materials Chemistry; materialkemi;

   Sammanfattning : Additive manufacturing (AM) as a manufacturing process has, in recent years, become widely accepted as capable of manufacturing parts that will be used in end products. In this thesis, stainless steel grade 316L parts are manufactured using two different powder bed fusion techniques, selective laser melting (SLM) and electron beam melting (EBM). LÄS MER

4. 3. Spark Plasma Sintering of Si3N4-based Ceramics : Sintering mechanism-Tailoring microstructure-Evaluationg properties

   Författare :Hong Peng; Zhijian (James) Shen; Mats Nygren; Michael J. Hoffmann; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; spark plasma sintering; silicon nitride ceramics; grain growth kinetic; superplasiticity; liqiud phase sintering; Chemistry; Kemi;

   Sammanfattning : Spark Plasma Sintering (SPS) is a promising rapid consolidation technique that allows a better understanding and manipulating of sintering kinetics and therefore makes it possible to obtain Si3N4-based ceramics with tailored microstructures, consisting of grains with either equiaxed or elongated morphology. The presence of an extra liquid phase is necessary for forming tough interlocking microstructures in Yb/Y-stabilised α-sialon by HP. LÄS MER