Effect of Processing Parameters on Interlayer Fracture Toughness of Fused Filament Fabrication Thermoplastic Materials

Author(s):  
Devin J. Young ◽  
Cara Otten ◽  
Michael W. Czabaj
Alloy Digest ◽  
2004 ◽  
Vol 53 (7) ◽  

Abstract ATI 425 was originally developed for hot-rolled armor plate to provide ballistic protection comparable to Ti-6Al-4V and has been evaluated against a variety of projectile threats for use as armor. While processing the alloy for armor plate applications, it was observed that the material exhibited very good hot workability, permitting a more lenient window of processing parameters than necessary for Ti-6Al-4V. Versatility then expanded, and applications now exist in the chemical process industry (CPI) and in the aerospace industry. This datasheet provides information on composition, physical properties, and tensile properties as well as fracture toughness and fatigue. It also includes information on corrosion resistance. Filing Code: TI-133. Producer or source: ATI Wah Chang, Allegheny Technologies. Originally published March 2004, revised July 2004.


2021 ◽  
pp. 089270572110214
Author(s):  
Weiller M Lamin ◽  
Flávio LS Bussamra ◽  
Rafael TL Ferreira ◽  
Rita CM Sales ◽  
José E Baldo

This work presents the experimental determination of fracture mechanics parameters of composite specimens manufactured by fused filament fabrication (FFF) with continuous carbon fiber reinforced thermoplastic filaments, based on Linear Elastic Fracture Mechanics (LEFM). The critical mode I translaminar fracture toughness (KIc) and the critical energy release rate (GIc) are found for unidirectional and cross-ply laminates. The specimens were submitted to quasi-static tensile testing. Digital Image Correlation (DIC) is used to find the stress field. The stress fields around the crack tip are compared to linear elastic finite element simulations. The results demonstrate the magnitude of fracture toughness is in the same range as for polymers and some metals, depending on lay-up configuration. Besides, fractographic analyses show some typical features as river lines, fiber impression, fiber pulls-out and porosity aspects.


2020 ◽  
pp. 089270572097062
Author(s):  
Sudhir Kumar ◽  
Rupinder Singh ◽  
TP Singh ◽  
Ajay Batish

Fused filament fabrication (FFF) is one of the low cost additive manufacturing (AM) techniques capable of printing complex design (both with commercial and non-commercial feedstock filaments by using different processing parameters). In this paper a comprehensive review has been prepared on FFF operating capabilities from thermoplastics material’s view point. Various thermoplastic materials and composites available commercially and prepared at laboratory scale have been categorized based upon the reported studies performed (for thermal stability, mechanical properties etc.). It was observed that the nano composite based feed stock filament (prepared at lab scale) have edge over the micro-composites from thermo-mechanical properties view point. Further it has been noticed that the 3D printing is in changing phase and moving towards 4D printing of smart composites and designs. But hitherto little has been reported on printing of smart material with FFF platform. Further studies may be focused on printing of smart materials (both micro and nano composites) with FFF, as the low cost 3D printing solution in different engineering applications.


Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 819 ◽  
Author(s):  
Andrea Dorigato ◽  
Daniele Rigotti ◽  
Alessandro Pegoretti

The aim of this work was the development of a thermoplastic/thermosetting combined system with a novel production technique. A poly(caprolactone) (PCL) structure has been designed and produced by fused filament fabrication, and impregnated with an epoxy matrix. The mechanical properties, fracture toughness, and thermal healing capacities of this blend (EP-PCL(3D)) were compared with those of a conventional melt mixed poly(caprolactone)/epoxy blend (EP-PCL). The fine dispersion of the PCL domains within the epoxy in the EP-PCL samples was responsible of a noticeable toughening effect, while in the EP-PCL(3D) structure the two phases showed an independent behavior, and fracture propagation in the epoxy was followed by the progressive yielding of the PCL domains. This peculiar behavior of EP-PCL(3D) system allowed the PCL phase to express its full potential as energy absorber under impact conditions. Optical microscope images on the fracture surfaces of the EP-PCL(3D) samples revealed that during fracture toughness tests the crack mainly propagated within the epoxy phase, while PCL contributed to energy absorption through plastic deformation. Due to the selected PCL concentration in the blends (35 vol %) and to the discrepancy between the mechanical properties of the constituents, the healing efficiency values of the two systems were rather limited.


1998 ◽  
Vol 551 ◽  
Author(s):  
P.S. Chen ◽  
W.P. Stanton

AbstractAt Marshall Space Flight Center (MSFC), a new aging technique has been developed that can significantly enhance the cryogenic fracture toughness (CFT) of Alloy 2195, as well as reducing the statistical spread of fracture toughness values. This technique improves cryogenic properties by promoting T1 nucleation and growth in the matrix, so that T1 nucleation and growth can be suppressed in the subgrain boundaries. It also minimizes mechanical property scatter due to unavoidable variations in thermomechanical processing parameters and alloy chemistry.


2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Chitralekha Nahar ◽  
Pavan Kumar Gurrala

Purpose The thermal behavior at the interfaces (of the deposited strands) during fused filament fabrication (FFF) technique strongly influences bond formation and it is a time- and temperature-dependent process. The processing parameters affect the thermal behavior at the interfaces and the purpose of the paper is to simulate using temperature-dependent (nonlinear) thermal properties rather than constant properties. Design/methodology/approach Nonlinear temperature-dependent thermal properties are used to simulate the FFF process in a simulation software. The finite-element model is first established by comparing the simulation results with that of analytical and experimental results of acrylonitrile butadiene styrene and polylactic acid. Strand temperature and time duration to reach critical sintering temperature for the bond formation are estimated for one of the deposition sequences. Findings Temperatures are estimated at an interface and are then compared with the experimental results, which shows a close match. The results of the average time duration (time to reach the critical sintering temperature) of strands with the defined deposition sequences show that the first interface has the highest average time duration. Varying processing parameters show that higher temperatures of the extruder and envelope along with higher extruder diameter and lower convective heat transfer coefficient will have more time available for bonding between the strands. Originality/value A novel numerical model is developed using temperature-dependent (nonlinear) thermal properties to simulate FFF processes. The model estimates the temperature evolution at the strand interfaces. It helps to evaluate the time duration to reach critical sintering temperature (temperature above which the bond formation occurs) as it cools from extrusion temperature.


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