This document discusses the stereolithographic ceramic manufacturing (SLCM) process for producing bioactive glass ceramic structures. The SLCM process uses digital light processing to layer-by-layer print, debind, and sinter a bioactive glass ceramic slurry into dense 3D parts. Testing showed the bioactive glass ceramic parts produced using SLCM had a density of 2.7 g/cm3 and a high biaxial bending strength of 124 MPa, comparable to natural cortical bone. The homogeneous microstructure and low defect rate contributed to the high strength. The SLCM process enables the precise production of complex bioactive glass ceramic scaffolds and structures for applications in bone repair and replacement.
Synthesis and testing of dental ceramicIJERA Editor
Zirconia has been recently introduced in prosthetic dentistry for the fabrication of crowns and fixed partial dentures, in combination with CAD/CAM techniques. Zirconia stabilized with Y2O3 has the best properties for these applications. This project aims at producing cast Zirconia blocks primarily for dental application that is more cost effective and biocompatible in comparison to the commercially available zirconia. A simple co-precipitation method was used to produce the zirconia powder; simple, inexpensive and indigenous method of uniaxial compression was employed to cast the zirconia pellet. Further studies have to be carried out to study and improve the densification behaviour, biocompatibility, aesthetics and resistance to masticatory force.
EXPERIMENTAL STUDY ON STRENGTH BEHAVIOUR OF SELF COMPACTING CONCRETE USING RE...AM Publications
The construction of modern structures alarming the attention of use of materials with improved properties
in respect of strength, stiffness, toughness and durability. Concrete is one of the most widely used construction material
having several advantages such as high strength, good mould ability and high durability. The major disadvantages of
concrete are its poorer tensile strength and lesser ductility (toughness). Conventional concrete used in building
construction and engineering applications requires compaction to attain strength, durability and homogeneity. The
typical method of compaction, by vibration, generates delays and additional costs in projects and could pose a serious
health hazard due to noise pollution in and around construction sites. Self Compacting Concrete (SCC) is a concrete
which is highly flowble, can flows readily into place, fill the formwork without any compaction and without undergoing
any significant segregation. Recycling is the act of processing the used material for creating a new useful product.
Construction and Demolished waste also generate Recycled Aggregate (RA). Such a Recycled Aggregate proved to be a
reliable alternative to Natural Aggregates (NA) in concrete. There is a growing need for renovation from a usual
consumption based society to a sustainable society owing the natural environment pollution, exhaustion of natural
resources and as decreasing capacity of disposal facilities for final waste. Use of aggregates from Building Demolished
Waste (BDW) in structural concrete is definitely an important stride. Use of RA in developing SCC is certainly a novel
thought towards achieving a sustainable concrete. There is a pressing demand for the use of Recycled Aggregate in
recent concretes, as sustainability is given the highest importance in today’s world. This has necessitated the make use
of Recycled Aggregates in SCC and fibre based SCC. Hence Reinforced Self Compacting Concrete using Recycled
Aggregate with fibres may be a potential material in construction. In order to clearly understand the performance of
such a concrete, there is a call for to study the stress-strain and flexural strength behaviour. The present study focuses
on flexural bond strength behaviour of Fibre Reinforced Self Compacting Concrete by replacing the natural Aggregate
with Recycled Aggregate. BDW is used as coarse aggregate in the concrete, with an aim to achieve sustainable concrete.
Synthesis and testing of dental ceramicIJERA Editor
Zirconia has been recently introduced in prosthetic dentistry for the fabrication of crowns and fixed partial dentures, in combination with CAD/CAM techniques. Zirconia stabilized with Y2O3 has the best properties for these applications. This project aims at producing cast Zirconia blocks primarily for dental application that is more cost effective and biocompatible in comparison to the commercially available zirconia. A simple co-precipitation method was used to produce the zirconia powder; simple, inexpensive and indigenous method of uniaxial compression was employed to cast the zirconia pellet. Further studies have to be carried out to study and improve the densification behaviour, biocompatibility, aesthetics and resistance to masticatory force.
EXPERIMENTAL STUDY ON STRENGTH BEHAVIOUR OF SELF COMPACTING CONCRETE USING RE...AM Publications
The construction of modern structures alarming the attention of use of materials with improved properties
in respect of strength, stiffness, toughness and durability. Concrete is one of the most widely used construction material
having several advantages such as high strength, good mould ability and high durability. The major disadvantages of
concrete are its poorer tensile strength and lesser ductility (toughness). Conventional concrete used in building
construction and engineering applications requires compaction to attain strength, durability and homogeneity. The
typical method of compaction, by vibration, generates delays and additional costs in projects and could pose a serious
health hazard due to noise pollution in and around construction sites. Self Compacting Concrete (SCC) is a concrete
which is highly flowble, can flows readily into place, fill the formwork without any compaction and without undergoing
any significant segregation. Recycling is the act of processing the used material for creating a new useful product.
Construction and Demolished waste also generate Recycled Aggregate (RA). Such a Recycled Aggregate proved to be a
reliable alternative to Natural Aggregates (NA) in concrete. There is a growing need for renovation from a usual
consumption based society to a sustainable society owing the natural environment pollution, exhaustion of natural
resources and as decreasing capacity of disposal facilities for final waste. Use of aggregates from Building Demolished
Waste (BDW) in structural concrete is definitely an important stride. Use of RA in developing SCC is certainly a novel
thought towards achieving a sustainable concrete. There is a pressing demand for the use of Recycled Aggregate in
recent concretes, as sustainability is given the highest importance in today’s world. This has necessitated the make use
of Recycled Aggregates in SCC and fibre based SCC. Hence Reinforced Self Compacting Concrete using Recycled
Aggregate with fibres may be a potential material in construction. In order to clearly understand the performance of
such a concrete, there is a call for to study the stress-strain and flexural strength behaviour. The present study focuses
on flexural bond strength behaviour of Fibre Reinforced Self Compacting Concrete by replacing the natural Aggregate
with Recycled Aggregate. BDW is used as coarse aggregate in the concrete, with an aim to achieve sustainable concrete.
Investigation on the effect of composition of calcium carbonate, cpw and dop ...eSAT Journals
Abstract
One of the biggest challenges in wire insulation industries is the proper governance of its raw materials to form the standardized product. The use of plasticizers has been well investigated and their utilization is very abundant. The ratio of CaCO3, CPW and DOP plays a very important role in determination of the tensile strength of PVC insulation. This paper focuses on the effect of CaCO3, CPW and DOP on the tensile strength of the PVC compounding having PVC resin at hold value of 45%. Unlike other papers this paper enumerates the effect of several components of the mixture simultaneously. The CaCO3 content ranges from 23.50-29.82 %, CPW ranges 8.7-13.04 % and DOP 10.0-15.04 % by weight. The optimum results for Ultimate Tensile Strength came out with 23.52% CaCO3, 13.0% CPW and 14.75% DOP.
Keywords: PVC Resin, CaCO3, CPW, DOP, PVC compounding, Ultimate Tensile Strength
Investigation on the effect of composition of calcium carbonate, cpw and dop ...eSAT Journals
Abstract
One of the biggest challenges in wire insulation industries is the proper governance of its raw materials to form the standardized product. The use of plasticizers has been well investigated and their utilization is very abundant. The ratio of CaCO3, CPW and DOP plays a very important role in determination of the tensile strength of PVC insulation. This paper focuses on the effect of CaCO3, CPW and DOP on the tensile strength of the PVC compounding having PVC resin at hold value of 45%. Unlike other papers this paper enumerates the effect of several components of the mixture simultaneously. The CaCO3 content ranges from 23.50-29.82 %, CPW ranges 8.7-13.04 % and DOP 10.0-15.04 % by weight. The optimum results for Ultimate Tensile Strength came out with 23.52% CaCO3, 13.0% CPW and 14.75% DOP.
Keywords: PVC Resin, CaCO3, CPW, DOP, PVC compounding, Ultimate Tensile Strength
Effect of stacking sequence and hybridization on the tensile and flexural properties of composite
laminates between basalt, jute and flax with E-glass reinforced epoxy have been investigated experimentally. It
was found that stacking sequence is not highly significant on tensile properties, contrasting with flexural strength
and modulus which were strongly dependent on the hybrid configuration between sandwich-like (SL) and
intercalation (IC) sequences. Specific modulus based on the variation densities of the hybrid laminates was used
to discover the best combination either basalt, jute or flax with E-glass exhibits superior properties concerning
on the strength to weight- ratio. Hence, stacking sequences and material selection are among predominant factors
that influence on mechanical properties and very crucial in designing composite hybrid system to meet the desired
requirements.
Experimental Study on Plastic Vastum as a Coarse Aggregate Quia Structural Co...ijtsrd
Due to speedy industrialization and urbanization in the united states lot of infrastructure trends are taking place. This technique has in flip led questions to mankind to remedy the troubles generated through this growth. The troubles described are acute scarcity of constructional materials, improved productiveness of waste and other products. In this task M30 grade concrete is taken and waste plastic is used as modifier. Tests had been carried out on coarse aggregates, high quality aggregates, cement and modifiers plastic waste to decide their bodily properties. Trail mixes are organized with 5 , 10 and 15 of plastic aggregates as the substitute for sand in M30 grade of concrete. Based on the mechanical power of concrete, it is found that 5 substitute of sand with plastic aggregates is the superior content. A. Saravanan | D. Kanagaraj "Experimental Study on Plastic Vastum as a Coarse Aggregate Quia Structural Concrete" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-3 , April 2020, URL: https://www.ijtsrd.com/papers/ijtsrd30624.pdf Paper Url :https://www.ijtsrd.com/engineering/structural-engineering/30624/experimental-study-on-plastic-vastum-as-a-coarse-aggregate-quia-structural-concrete/a-saravanan
Fabrication and Experimental Investigation of Mechanical Properties of Graphe...
Gmeiner_MSE_2014_Poster
1. Stereolithographic
layer-by-layer
printing
Debinding
Sintering
Lithography-based Additive Manufacturing
of Bioactive Glass Ceramics
Robert Gmeiner1*, Ileana Panaitescu1, Gerald Mitteramskogler1, Jakub Wojak1,
Aldo R. Boccaccini2, Jürgen Stampfl1
1Institute of Materials Science and Technology, Vienna University of Technology, Favoritenstraße 9-11/E308, A-1040 Vienna, Austria
2Institute for Biomaterials, University of Erlangen-Nuremberg, Cauerstrasse 6, 91058 Erlangen, Germany
*Corresponding author: robert.gmeiner@tuwien.ac.at (R. Gmeiner)
Introduction
1. Light source
2. DMD-chip (dynamic mask)
3. Optic
4. Material vat
5. Coating blade
6. Back light
7. Building platform
8. Load cell
9. Manufactured part
DLP-based Lithography
The additive manufacturing system used for this study is
based on the DLP (Digital Light Processing) technology
(see Figure 1). A Digital Mirror Device (DMD) chip acts as
an dynamic mask to expose a well defined area on the
bottom of a transparent material vat above an optical
system. The so generated pictures enable layer-by-layer
polymerization of a photosensitive resin resulting in 3-
dimensional objects. Curing takes place at wavelengths
around 460nm which means blue visible light. The
system used combines high optical resolution, allowing
voxel geometries of 25x25x25µm3, in a building area the
size of a coffee cup.
[1] R. Gmeiner, G. Mitteramskogler, A.R. Boccaccini, and J. Stampfl, “Stereolithographic Ceramic Manufacturing of High Strength Bioactive Glass”; Int. J. Appl. Ceram. Tec. 2014, DOI:10.1111/ijac.12325
[2] P. Tesavibul, R. Felzmann, S. Gruber, R. Liska, I. Thompson, A.R. Boccaccini, and J. Stampfl, “Processing of 45S5 Bioglass® by lithography-based additive manufacturing,” Mater. Lett., 74 81–84 (2012).
[3] L.L. Hench and T. Kokubo, “Properties of bioactive glasses and glass-ceramics”; pp. 355–363 in Handb. Biomater. Prop. Edited by J. Black and G. Hastings. Springer US, 1998.
Bioactive glasses and glass ceramics like the 45S5 formulation have been studied towards biocompatibility and –degradability for years. Nevertheless clinical applications as bone substitute or scaffold material are
highly limited because of their often poor mechanical behaviour. In this study we are able to provide a new production alternative for 45S5 bioactive glass structures resulting in parts with high density and
strength. By using the Stereolithographic Ceramic Manufacturing (SLCM) process it is possible to additively produce solid bulk glass ceramics as well as delicate scaffold structures. Recent developments in SLCM
slurry preparation together with an appropriate selection of raw materials led to 3D-parts with a very homogeneous microstructure and a density of about 2,7g/cm³. Due to the low number and small size of
defects, a high biaxial bending strength of 124MPa was achieved. Weibull distribution also underlines good process control showing a Weibull modulus of 8.6 and a characteristic strength of 131MPa for the
samples tested here. By reaching bending strength values of natural cortical bone, bioactive glasses processed with SLCM could eventually advance to be an interesting bone substitute material even in load
bearing applications.[1]
0,00
20,00
40,00
60,00
80,00
100,00
120,00
140,00
160,00
Bioactive glass
(Vitryxx®)
Biaxialbendingstrength[MPa]
y = 8,6205x - 42,033
-5
-4
-3
-2
-1
0
1
2
3
4,5 4,6 4,7 4,8 4,9 5 5,1 5,2
lnln(1/1-Pf)
ln(σ) [MPa]
Name [weight %]
SiO2 45,50
CaO 24,25
Na2O 24,25
P2O5 6,00
Table 1: Composition of the ‘bioactive
glass powder’ used (Vitryxx, Schott
AG, Mainz, Germany)
The 45S5 bioactive glass formulation is well known for its biocompatible and biodegradable
properties. The bioactive glass ceramic filling material used in this study is comparable to the 45S5
formulation (see Table 1) and available under its commercial name Vitryxx® (Schott AG, Mainz,
Germany). By using small grained powder we have been able to generate homogenious slurries
without perturbing agglomerates, thus enabling smooth and defect free green part production.
Stereolithographic green part generation is subsequently followed by a debinding cycle, eliminating
the organic binder compounds. Dense glass ceramic parts can be manufactured using a final
sintering step, completing the SLCM process.
Mechanical characterization of the resulting
bioactive glass ceramics included density
measurements, biaxial bending tests, EDX
analysis and SEM fracture inverstigations.
Tested specimens show suprisingly high biaxial
bending strength (124 MPa) compared to other
production techniques known in literature (see
Table 2). This is understood to be related to the
high density found for the glass ceramic parts.
SEM images confirm the homogenious
microstructure of the generated parts, showing
only a few minor defects on fracture surfaces
(see Figure 3). Weibull statistics reveal good
process control, resulting in a Weibull modulus
of 8.6 for biaxial beding test specimen.
SLCM enables high feature resolution as well as outstanding material properties and can therefore be considered as a
possible key technology for manufacturing delicate bioactive scaffolds or patient specific bone restorations out of
bioactive glass ceramics like the 45S5 formulation (see Figure 4). The technology could assist bone cancer treatment or
pioneer new approaches in maxillofacial surgery, valuing the huge efforts undertaken to understand bioactive glass
ceramic behaviour.
Bioactive glass 45S5
Density of sintered samples [g/cm³] 2,701
Biaxial bending strength [MPa] 124 ±17
Biaxial bending strength in literature [MPa] 422, 403
Weibull modulus [ - ] 8.6
Weibull characteristic strength [MPa] 131
Table 2: Material properties of 45S5 bioactive glass ceramic
manufactured by SLCM-technology
Figure 2: Biaxial bending strength and Weibull modulus of 45S5 bioactive glass used in the
stereolithographic ceramic manufacturing process (accord. to ISO 6872)
Figure 3: SEM images of fracture surfaces of 45S5 test specimen are showing high density and
only a few, minor defects in the microstructure of the bioactive glass ceramic
Bioactive Glass
Material Properties
Conclusion
Figure 1: DLP-based stereolithographic printing process
Figure 4: Bioactive glass ceramic scaffold based on µCT data of human femoral bone
(spongiosa), manufactured by SLCM process