Humidity-Dependent Flaw Sensitivity in the Fracture Toughness of 3d-Printed Nano-Ceramics

2020 ◽  
Author(s):  
Edoardo Rossi ◽  
Jens Bauer ◽  
Marco Sebastiani
Keyword(s):  
Fracture Toughness ◽  
3D Printed ◽  
Flaw Sensitivity

scholarly journals Fracture Toughness of Hybrid Components with Selective Laser Melting 18Ni300 Steel Parts

2018 ◽  
Vol 8 (10) ◽  
pp. 1879 ◽  
Author(s):  
Luis Santos ◽  
Joel de Jesus ◽  
José Ferreira ◽  
José Costa ◽  
Carlos Capela
Keyword(s):  
Fracture Toughness ◽  
Selective Laser Melting ◽  
Compact Tension ◽  
Powder Materials ◽  
Layer By Layer ◽  
Laser Melting ◽  
Conventional Steel ◽  
Scan Rate ◽  
Aisi H13 ◽  
3D Printed

Selective Laser Melting (SLM) is currently one of the more advanced manufacturing and prototyping processes, allowing the 3D-printing of complex parts through the layer-by-layer deposition of powder materials melted by laser. This work concerns the study of the fracture toughness of maraging AISI 18Ni300 steel implants by SLM built over two different conventional steels, AISI H13 and AISI 420, ranging the scan rate between 200 mm/s and 400 mm/s. The SLM process creates an interface zone between the conventional steel and the laser melted implant in the final form of compact tension (CT) samples, where the hardness is higher than the 3D-printed material but lower than the conventional steel. Both fully 3D-printed series and 3D-printed implants series produced at 200 mm/s of scan rate showed higher fracture toughness than the other series built at 400 mm/s of scan rate due to a lower level of internal defects. An inexpressive variation of fracture toughness was observed between the implanted series with the same parameters. The crack growth path for all samples occurred in the limit of interface/3D-printed material zone and occurred between laser melted layers.

scholarly journals Guiding and Trapping Cracks With Compliant Inclusions for Enhancing Toughness of Brittle Composite Materials

2020 ◽  
Vol 87 (3) ◽  
Author(s):  
Neal R. Brodnik ◽  
Chun-Jen Hsueh ◽  
Katherine T. Faber ◽  
Blaise Bourdin ◽  
Guruswami Ravichandran ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Elastic Modulus ◽  
Heterogeneous Material ◽  
Effective Elastic Modulus ◽  
Elastic Compliance ◽  
Field Approach ◽  
Numerical Predictions ◽  
The Matrix ◽  
3D Printed ◽  
Square Array

Abstract The problem of toughening heterogeneous materials with a stiff matrix and compliant inclusions is investigated through numerical simulations and experiments. Specifically, the problem of optimizing a combination of effective toughness and effective elastic modulus in the context of a square array of compliant inclusions in a stiff matrix is explored. Crack propagation in the heterogeneous material is simulated using a variational phase-field approach. It is found that the crack can meander between or get attracted to and trapped in the inclusions. Composite specimens with a stiff matrix and compliant circular inclusions were 3D printed, and their fracture toughness was measured using a specially designed loading fixture. The experimental results show agreement with the numerical predictions by demonstrating the attraction and trapping of cracks in the inclusions. This study demonstrates the potential for significant enhancement of toughness through elastic compliance contrast between the matrix and the inclusion without notably compromising the effective elastic modulus of the composite material.

Effect of Raster Orientation on Fracture Toughness Properties of 3D Printed ABS Materials and Structures

2016 ◽  
Author(s):  
Amit Khatri ◽  
Ashfaq Adnan
Keyword(s):  
Fracture Toughness ◽  
Process Parameters ◽  
Experimental Studies ◽  
Processing Parameters ◽  
Deposition Method ◽  
Layer Height ◽  
Fused Deposition ◽  
3D Printed ◽  
Cracked Structures ◽  
Cracked Specimens

Additive manufacturing is a rapidly growing cutting edge technology. Number of experimental studies have shown that strength of product manufactured by additive Fused Deposition Method (FDM) is influenced by different processing parameters involved during manufacturing. This research paper presents experimental and theoretical investigation of fracture toughness of ABS material fabricated with variation in some of process parameters such as Axis Orientations, Raster Orientation, Infill Percentage, Layer Height and Number of Shells. Experiment was designed to manufacture number of cracked specimens with variation in process parameters, measure their tensile strengths for fracture toughness and compare stress intensity factor (SIF) for all of the specimens. This study helps to understand, how different raster orientations affect the fracture toughness of 3D printed structures and also tells us under which process parameters additive manufactured cracked structures provide better strength.

Testing Impact Load Cell Calculations of Material Fracture Toughness and Strength Using 3D-Printed Sandstone

2019 ◽  
Vol 38 (2) ◽  
pp. 1065-1096
Author(s):  
Karina Barbosa ◽  
Rick Chalaturnyk ◽  
Benjamin Bonfils ◽  
Joan Esterle ◽  
Zhongwei Chen
Keyword(s):  
Fracture Toughness ◽  
Impact Load ◽  
Load Cell ◽  
3D Printed ◽  
Material Fracture

Study of the anisotropy of the properties of the ceramic cutting insert obtained by the LCM technology of 3D printing from the composite Al2O3/ZrO2 (ZTA)

2021 ◽  
Vol 87 (11) ◽  
pp. 64-69
Author(s):  
G. V. Shcherbak ◽  
A. A. Murashov ◽  
K. E. Smetanina ◽  
M. M. Vostokov ◽  
M. S. Boldin
Keyword(s):  
Fracture Toughness ◽  
Phase Composition ◽  
3D Printing ◽  
Bending Test ◽  
Indentation Method ◽  
Load Range ◽  
High Adhesion ◽  
Cutting Insert ◽  
3D Printed ◽  
Knoop Indenter

The anisotropy of the properties of a ceramic cutting insert (for three faces) obtained by the lithography-based technology from the Al2O3 + ZrO2 composite has been studied. The study was carried out using the indentation method and Mayer’s law. This method, in contrast to the bending test, excludes the sample destruction. All the studies were carried out on three faces of a ceramic cutting insert made of a composite Al2O3 + ZrO2. The behavior of the Mayer index was studied in the range of loads from 2 to 20 kg and from 0.2 to 1 kg. The results of studying the density, phase composition and microstructure of each face of the sample are presented. The study of the adhesion of the printed layers were also carried out using a Knoop indenter. No anisotropy of the hardness was observed in the load range up to 10 kg. It is shown that a layered structure present in the sample, contributes to the hardness anisotropy under the load of 20 kg and more. No anisotropy of the fracture toughness is observed in the load range of 2 – 20 kg. The results of using a Knoop indenter revealed a high adhesion between 3D printed layers. Studies using a Knoop indenter have indicated high adhesion between the layers of 3D printing.

scholarly journals 3D-Printed vs. Heat-Polymerizing and Autopolymerizing Denture Base Acrylic Resins

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5781
Author(s):  
Leila Perea-Lowery ◽  
Mona Gibreel ◽  
Pekka K. Vallittu ◽  
Lippo V. Lassila
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Elastic Modulus ◽  
Flexural Strength ◽  
Water Solubility ◽  
Base Material ◽  
Acrylic Resin ◽  
Denture Base ◽  
3D Printed ◽  
Work Of Fracture

The aim of this work was to investigate the effect of two post-curing methods on the mechanical properties of a 3D-printed denture base material. Additionally, to compare the mechanical properties of that 3D-printed material with those of conventional autopolymerizing and a heat-cured denture base material. A resin for 3D-printing denture base (Imprimo®), a heat-polymerizing acrylic resin (Paladon® 65), and an autopolymerizing acrylic resin (Palapress®) were investigated. Flexural strength, elastic modulus, fracture toughness, work of fracture, water sorption, and water solubility were evaluated. The 3D-printed test specimens were post-cured using two different units (Imprimo Cure® and Form Cure®). The tests were carried out after both dry and 30 days water storage. Data were collected and statistically analyzed. Resin type had a significant effect on the flexural strength, elastic modulus, fracture toughness, and work of fracture (p < 0.001). The flexural strength and elastic modulus for the heat-cured polymer were significantly the highest among all investigated groups regardless of the storage condition (p < 0.001). The fracture toughness and work of fracture of the 3D-printed material were significantly the lowest (p < 0.001). The heat-cured polymer had the lowest significant water solubility (p < 0.001). The post-curing method had an impact on the flexural strength of the investigated 3D-printed denture base material. The flexural strength, elastic modulus, fracture toughness, work of fracture of the 3D-printed material were inferior to those of the heat-cured one. Increased post-curing temperature may enhance the flexural properties of resin monomers used for 3D-printing dental appliances.

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