Manufacturing and characterization of uniformly porous and graded porous polymeric structures via selective laser sintering

Download

index.pdf

Date

2009

Author

Jande, Yusufu Abeid Chande

Metadata

Show full item record

Item Usage Stats

257
views

92
downloads

Selective laser sintering is a rapid prototyping method (RP), which was originally developed, along with other RP methods, to speed up the prototyping stage of product design. The sole needed input for production being the solid model of the part, the mold/tool-free production characteristics and the geometric part complexity that can be achieved due to layer-by-layer production have extended the applicability/research areas of these methods beyond prototyping towards new applications and material development. Local pore formation in a part that occurs as a result of the discrete manufacturing nature of selective laser sintering is normally considered a defect. In the current research, this is viewed as an opportunity for material development: Exploitation of rapid prototyping methods to produce composites/functionally graded materials with controlled porous structures. That the material interior structure (porous structure) and exterior shape are formed during the same course renders selective laser sintering process as an attractive manufacturing alternative for producing complex-geometry composite/porous materials, which may be difficult or impossible to manufacture with other techniques. In this thesis, the use of selective laser sintering (a rapid prototyping method) in producing uniformly porous and graded polymeric graded porous structures is studied. The material used was polyamide powder (PA 2200) and the selective laser sintering machine used was the EOSINT P 380 system. In this research, three process parameters of the SLS system, the hatching distance, the laser power and the laser scanning speed were varied to produce parts that have different porosities. Porous parts with a homogenous porous microstructure (uniformly porous parts) could be produced, as well as graded porous parts. The results of uniformly porous structure production were utilized to build graded porous structures by imparting different porosities along a certain direction within a single part. Both, uniformly porous and graded structures were characterized physically and mechanically. The porous parts (both uniformly porous and graded porous) were infiltrated with epoxy resin to produce epoxy-PA composites and graded materials. The physical and mechanical properties of these parts were compared with those of the uninfiltrated (porous PA) structures

Subject Keywords

Mechanical engineering.

URI

http://etd.lib.metu.edu.tr/upload/12611406/index.pdf
https://hdl.handle.net/11511/19305

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Mechanical characterization and modelling of porous polymeric materials manufactured by selective laser sintering Tekin, Cevdet Murat; Dağ, Serkan; Department of Mechanical Engineering (2009) Rapid prototyping methods embrace a family of manufacturing methods that are developed to speed up the prototyping stage of product design. The sole needed input for production being the solid model of the part, mold/tool-free production characteristics and the geometric part complexity that can be achieved due to layer-by-layer production have extended the applicability/research areas of these methods beyond prototyping. Local pore formation in part that occurs as a result of the discrete manufacturing nat...
Effect of production parameters on porosity and hole properties in laser sintering rapid prototyping process İlkgün, Özkan; Erdal Erdoğmuş, Merve; Department of Mechanical Engineering (2005) Selective laser sintering (SLS) is a rapid prototyping method in which three-dimensional objects are constructed by sintering thin layers of a variety of powdered materials via laser beam. In SLS, as in most other Rapid Prototyping methods, the produced parts exhibit varying degrees of intrinsic porosity due to the discrete nature of layer-by-layer production. Selective scanning and discrete bonding of individual particles or clusters of particles impart local porosity, which is mostly an undesired trait as...
Development of postprocessor, simulation and verification software for a five-axis CNC milling machine Cengiz, Ender; Gökler, Mustafa İlhan; Department of Mechanical Engineering (2005) Five-axis CNC milling machine tools bring great facility to produce complex workpieces with increased dimensional accuracy and better surface quality in shorter machining times. However, kinematics of five-axis machine tools has a complex form which makes it difficult to operate these machine tools properly. The difficulty arises from the complexity of NC-Code generation and tool path verification. Collision of machine tool or setup components with each other is a severe problem in five-axis machining opera...
A Feature Based Design Software for Parts To Be Machined in a Four-Axis CNC Lathe Hatipoğlu, Demiralp; Arıkan, Mehmet Ali Sahir; Department of Mechanical Engineering (2005) A previously developed feature library and algorithm are improved in order to develop a software capable of designing of parts to be manufactured using a four-axis CNC lathe. The developed program is composed of sections which are; part geometry design, process planning, cutting tool and machining parameter selection, part program generation and G-code simulation for verification. The developed program is capable of designing parts which contain axisymetric features for turning and related operations, and n...
Analysis and modeling of plastic wrinkling in deep drawing Yalçın, Serhat; Oral, Süha; Kaftanoğlu, Bilgin; Department of Mechanical Engineering (2010) Deep drawing operations are crucial for metal forming operations and manufacturing. Obtaining a defect free final product with the desired mechanical properties is very important for fulfilling the customer expectations and market competitions. Wrinkling is one of the fatal and most frequent defects that must be prevented. This study focuses on understanding the phenomenon of wrinkling and probable precautions that can be applied. In this study, dynamic – explicit commercial finite element code is used to s...

Citation Formats

Y. A. C. Jande, “Manufacturing and characterization of uniformly porous and graded porous polymeric structures via selective laser sintering,” M.S. - Master of Science, Middle East Technical University, 2009.