...Zheren Song; Xinming Wang; Yuanyuan Gao; Junbo Son; Jianguo Wu Metal additive manufacturing (AM) has been receiving unprecedented attention for its transformational role in extending the AM materials from polymers to various metals. However, various quality issues, especially porosity...

... of both spherical and irregular-shaped pores in samples built by GA powder. Additionally, they showed deprived mechanical properties due to the higher porosity contents which can form stress-concentrated areas. Email: kenevisims10@mails.tsinghua.edu.cn 1 Corresponding author. Email: linfeng...

... properties. It is shown that an increase in porosity from 49% to 54% during the etching is mainly due to an increase in the number of 100 to 800 μm-diameter pores, from 30% to 50% of them measuring from 100 to 300 μm in size. These changes in the porous structure lead to a significant increase of its...

... fusion porosity Laser powder bed fusion (LPBF) process is a metal-based additive manufacturing (AM) technology, which utilizes a laser to sequentially melt the powder particles. Due to the line-by-line and layer-by-layer scanning process, complex geometries can be fabricated using LPBF. However...

...Subin Shrestha; Thomas Starr; Kevin Chou Porosity is an inherent attribute in selective laser melting (SLM) and profoundly degrades the build part quality and its performance. This study attempts to understand and characterize the keyhole pores formed during single-track scanning in SLM. First, 24...

...Petr Hermanek; Filippo Zanini; Simone Carmignato Manufacturing technologies deliver products that can suffer from various defects, one of which is internal porosity. Pores are present in most of the parts produced by, e.g., casting, additive manufacturing, and injection molding and can...

... porosity distribution over the spatial domain of the laminate. All matrix and vector quantities in the above equations are defined in Table 1 . Stresses are updated after each iteration using the following equation: (17) σ k = σ k − 1 + D S K k − 1 B k Δ...

... to fabricate porous structures. However, these methods can only fabricate simple geometries. In recent years, many studies have been done to use additive manufacturing (AM), e.g., stereolithography apparatus (SLA), in the fabrication of porous structure; however, the porosity that can be achieved is relatively...

... online December 12, 2014. Assoc. Editor: Wayne Cai. 15 07 2014 12 10 2014 12 12 2014 An investigation is reported on the characteristics of porosity formation in high power disk laser welding of AC-170PX (AA6014) alloy sheets (coated with titanium and zirconium) in two weld...

... a regular matrix of interconnecting pores, high strength, and high porosity. Manufacturing difficulties encourage the application of stamping and forming technologies to increase CVD reactor throughput and reduce materials wastes. In this study, the formability of TM was evaluated using a novel camera-based...

... is inelastic, dissipative force exits, leading to energy loss in every collision. The interparticle contact force is calculated based on the nonlinear Hertz theory. The packing structures quantified by porosity and the coordination number under different particle size distributions are discussed...

...J. J. Hernández-Ortega; R. Zamora; J. Palacios; J. López; F. Faura One of the most important problems encountered in die-casting processes is porosity due to air entrapment in the molten metal during the injection process. The aim of this work is to study experimentally and numerically...

... of the layer. They were systematically sensitive to both the powder material composition and the process parameters. 25 11 2008 18 05 2009 08 09 2009 coating techniques computerised tomography laser beam applications optical microscopy porosity rapid prototyping (industrial...

...M. G. Li; X. Y. Tian; X. B. Chen Dispensing technique is one of the promising solid freeform (SFF) methods to fabricate scaffolds with controllable pore sizes and porosities. In this paper, a model to represent the dispensing-based SFF fabrication process is developed. Specifically, the mechanical...

...R. Zamora; J. J. Hernandez-Ortega; F. Faura; J. Lopez; J. Hernandez The air entrapment mechanisms in die-casting injection chambers that may produce porosity in manufactured parts are analyzed in this work using visualization techniques of the flow in a transparent injection chamber model, using...

... underneath, laser scanning velocity, and initial porosity on the sintering process are investigated. 05 06 2006 28 04 2008 08 07 2008 finite volume methods laser sintering natural convection porosity powders solidification Selective laser sintering (SLS) is a rapid...

... consolidation strength and porosity were investigated. In addition, the achievable aspect ratio and taper angle were also discussed. 28 05 2007 09 03 2008 05 05 2008 compaction heat transfer hot working mass production porosity powders productivity sintering temperature...

... diagram. The ferritic and martensitic transformation as well as austenitization and tempering of martensite are considered. The influence of processing parameters such as laser power and traverse speed on the phase transformation and the consequent hardness are analyzed. The potential presence of porosity...

... reversible martensite-austenite transformation peaks that are the prerequisite for the shape memory effect (SME) in SMAs. DSC has also shown that quenching affects the peaks. The density of the produced parts was close to the theoretical density of the material as determined by porosity measurements. Finally...

... location and flow time data was derived. This approach was validated by both simulation and experimental studies. The results show that by using this method, permeability values of different fiber mat types or the relationship between permeability and fiber volume fraction (porosity) can be obtained...