Fabrication of high-performance silica-based ceramic cores through selective laser sintering combined with vacuum infiltration

Purpose – The purpose of this paper is to propose and evaluate the selection of materials for the selective laser sintering (SLS) process, which is used for low-volume production in the engineering (e.g. light weight machines, architectural modelling, high performance application, manufacturing of fuel cell, etc.), medical and many others (e.g. art and hobbies, etc.) with a keen focus on meeting customer requirements. Design/methodology/approach – The work starts with understanding the optimal process parameters, an appropriate consolidation mechanism to control microstructure, and selection of appropriate materials satisfying the property requirement for specific application area that leads to optimization of materials. Findings – Fabricating the parts using optimal process parameters, appropriate consolidation mechanism and selecting the appropriate material considering the property requirement of applications can improve part characteristics, increase acceptability, sustainability, life cycle and reliability of the SLS-fabricated parts. Originality/value – The newly proposed material selection system based on properties requirement of applications has been proven, especially in cases where non-experts or student need to select SLS process materials according to the property requirement of applications. The selection of materials based on property requirement of application may be used by practitioners from not only the engineering field, medical field and many others like art and hobbies but also academics who wish to select materials of SLS process for different applications.

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Control-Oriented Modeling and Repetitive Control in In-Layer and Cross-Layer Thermal Interactions in Selective Laser Sintering

ASME Letters in Dynamic Systems and Control ◽

10.1115/1.4046367 ◽

2020 ◽

Vol 1 (1) ◽

Author(s):

Dan Wang ◽

Tianyu Jiang ◽

Xu Chen

Keyword(s):

High Performance ◽

Selective Laser Sintering ◽

Repetitive Control ◽

Three Dimensional ◽

Process Variations ◽

Laser Sintering ◽

Laser Source ◽

Cross Layer ◽

Modeling And Control ◽

Melt Pool

Abstract Although laser-based additive manufacturing (AM) has enabled unprecedented fabrication of complex parts directly from digital models, broader adoption of the technology remains challenged by insufficient reliability and in-process variations. In pursuit of assuring quality in the selective laser sintering (SLS) AM, this paper builds a modeling and control framework of the key thermodynamic interactions between the laser source and the materials to be processed. First, we develop a three-dimensional finite element simulation to understand the important features of the melt pool evolution for designing sensing and feedback algorithms. We explore how the temperature field is affected by hatch spacing and thermal properties that are temperature-dependent. Based on high-performance computer simulation and experimentation, we then validate the existence and effect of periodic disturbances induced by the repetitive in- and cross-layer thermomechanical interactions. From there, we identify the system model from the laser power to the melt pool width and build a repetitive control algorithm to greatly attenuate variations of the melt pool geometry.

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A novel method based on selective laser sintering for preparing high-performance carbon fibres/polyamide12/epoxy ternary composites

Scientific Reports ◽

10.1038/srep33780 ◽

2016 ◽

Vol 6 (1) ◽

Cited By ~ 31

Author(s):

Wei Zhu ◽

Chunze Yan ◽

Yunsong Shi ◽

Shifeng Wen ◽

Jie Liu ◽

...

Keyword(s):

High Performance ◽

Selective Laser Sintering ◽

Laser Sintering ◽

Carbon Fibres ◽

Novel Method

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Freeform Fabrication of High Performance Titanium Components via SLS/HIP

MRS Proceedings ◽

10.1557/proc-542-45 ◽

1998 ◽

Vol 542 ◽

Author(s):

S. Das ◽

J. J. Beaman ◽

M. Wohlert ◽

D. L. Bourell

Keyword(s):

High Performance ◽

Selective Laser Sintering ◽

Hot Isostatic Pressing ◽

Laser Sintering ◽

Single Step ◽

Isostatic Pressing ◽

Freeform Fabrication ◽

Post Process ◽

Processed Material ◽

Full Densification

AbstractThis paper presents the development of Selective Laser Sintering/Hot Isostatic Pressing (SLS/HIP) technology for production of functional high performance components in the titanium alloy Ti-6AI-4V. SLS/HIP is a net shape manufacturing technique that combines and exploits the freeform shaping capability of selective laser sintering and the full densification capability of hot isostatic pressing. The advantages of SLS combined with in situ HIP encapsulation include single step net shape canning, full densification by containerless HIP, no container-powder adverse interactions, reduced pre-processing time, and minimal post-process machining compared to conventional HIP of canned powders. Microstructure and mechanical properties of SLS processed and HIP post-processed Ti-6A1-4V are consistent with conventionally processed material. The potential of SLS/HIP technology was demonstrated by net shape fabricating a component to specification, namely the titanium guidance section housing base for the AIM-9 Sidewinder missile.

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Microstructures and Properties of Cu–AISI304 Parts Fabricated by Improved Selective Laser Sintering

Journal of Manufacturing Science and Engineering ◽

10.1115/1.3168444 ◽

2009 ◽

Vol 131 (4) ◽

Cited By ~ 1

Author(s):

Z. L. Lu ◽

J. H. Liu ◽

Y. S. Shi

Keyword(s):

High Performance ◽

Selective Laser Sintering ◽

Hot Isostatic Pressing ◽

Processing Parameters ◽

Laser Sintering ◽

Cold Isostatic Pressing ◽

Isostatic Pressing ◽

Cu Content ◽

Mechanical Performances ◽

Liquid Sintering

For fabricating complex AISI304 parts with high performance by advanced powder/metallurgy technologies, cold isostatic pressing (CIP) is introduced into selective laser sintering (SLS) combined with hot isostatic pressing (HIP), which is abbreviated to selective laser sintering/isostatic pressed (SLS/IP). The effect of processing parameters on the densification of Cu–AISI304 parts is analyzed and then the influence of Cu on their relative densities, metallurgical structures, and mechanical performances are investigated. The results show that relative densities of Cu–AISI304 parts fabricated by SLS/IP are mainly influenced by CIP pressure and sintering temperature, and it is interesting to find that the formula 1−D=(1−D0)e−kP is testified by the CIP of SLS/IP. There is an antidensification phenomenon resulting from Cu and AISI304 in liquid sintering, but the relative densities of Cu–AISI304 parts can be gradually improved in HIP with Cu content increasing from 1 wt % to 3 wt %. After the above-mentioned Cu–AIS304 parts are finally hot isostatic pressed, their metallurgical structures consist of sosoloid (Cu,Ni) and (Fe,Ni) besides austenite (Fe,Cr,Ni,C), their best mechanical performances are close to those of solution treated compact AISI304 when Cu content is 3 wt %.

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