Excellent Dimensional Accuracy Research Articles

A facile and sustainable integrated fabrication strategy for multi-performance 316L stainless steel

Additive manufacturing enables innovative design and integrated manufacturing of complex components. Metallic components with multi-performance and high reliability are always desirable for a broad range of high-end industries. Multi-material additive manufacturing is a promising way to provide multiple performances, yet there exist several persistent challenges on multi-material sustainability and recycling, interfacial defects and strength, dimensional accuracy and fineness, and manufacturing efficiency and cost, prohibiting its widespread practical applications. In this study, we introduce an additive/modification integrated manufacturing (AMIM) strategy for fabricating highly reliable multi-performance metals using only a single material with a one-step process. We demonstrate that, through a unique combination of pattern-induced orientation-consistent and layer-accumulated orientation-amplified mechanisms, the surface wear resistance performance of 316L stainless steels could be expanded to cover an exceptionally wide range from commercially available plastics to metals to ceramics. Furthermore, these strikingly different performances can be digitally programmed and precisely printed to form integrated 316L stainless steel components with excellent interfacial strength and high dimensional accuracy. This strategy paves a facile, inexpensive, and sustainable way to achieve multi-performance metals that are fully recyclable and environmentally friendly, serving as an alternative to the multi-material composite strategy.

Improved mechanical properties and dimensional accuracy of silica-based ceramic cores by Si3N4 addition

Silica-based ceramic cores are extensively used to form the complex hollow structure inside turbine blade. However, the excellent mechanical properties and high dimensional accuracy of ceramic cores are very crucial to obtain the hollow turbine blade with high precision, which is still a challenging work. In this study, silica-based ceramic cores with silicon nitride addition were prepared for improving the mechanical properties and dimensional accuracy. Results showed that the linear shrinkage of silica-based ceramic cores significantly decreased from 1.21 % to 0.087 % and the porosity gradually increased from 17.9 % to 22.1 % with the increase of Si3N4 content. The weight gain of cristobalite in the core samples after sintering first increased and then decreased, where the sample with 5 wt% Si3N4 had the maximum cristobalite content of 4.4 wt%. The appropriate Si3N4 content (5 wt%) in the silica-based ceramic cores could enhance the flexural strength at room temperature to 16.84 MPa by promoting densification process. However, the excess Si3N4 content (more than 10 wt%) could hinder the densification process and enlarge their porosity, decreasing the flexural strength at room temperature. Meanwhile, the high temperature strength at 1500 °C was decreased owing to the increasing porosity caused by the re-oxidation of Si3N4 particles. Therefore, it was concluded that the silica-based ceramic cores with 5 wt% Si3N4 showed higher mechanical properties and lower linear shrinkage, which offered a way to maintain the excellent mechanical properties and high dimensional accuracy of ceramic cores.

Research on design and milling performance of unequal gradient helix and variable pitch end mill

It is difficult to obtain excellent surface quality and dimensional accuracy of the low-rigidity frame and beam parts made by titanium alloy, due to the obvious vibration and large elastic deformation during side milling. The variable helix and pitch cutting tool is usually used to reduce vibration, which does not consider the unequable stiffness in the milling area. Therefore, the concept of Unequal Gradient Helix and Variable Pitch (UGHVP) is proposed in this research. The helix angles of the UGHVP vary with the stiffness of the milling area position, which will lead to milling forces and vibration decreasing as the stiffness weakens. As a result, the surface quality and dimensional accuracy will be increased, of which the advantages are analyzed. The mathematical models of the UGHVP circumferential cutting edges and groove sections are derived, which provide theoretical support for tool grinding. The models are visualized by numerical simulation. Finally, the comparison experiment with the conventional variable helix and pitch end mill was completed by side-milling the designed feature samples. The results showed that the milling forces perpendicular to the milling surface by the UGHVP were smaller and less fluctuating, which could obtain less elastic deformation theoretically. The milling vibration was smoother, especially when cutting in and out. Besides, the larger the axial depth of cut, the more obvious the superior performance of the UGHVP tool. Better surface quality and dimensional accuracy were obtained, which proved the excellent performance of the UGHVP.

A strategy to tailor the mechanical and degradation properties of PCL-PEG-PCL based copolymers for biomedical application

Biodegradable and biocompatible 3D printable biomaterials with tunable mechanical properties and degradation rate adapted to target tissues were urgently required to manufacture scaffolds for tissue regeneration. Herein, a strategy based on a series of copolymers are proposed where the mechanical and degradation properties can be optimized regarding the specific biological application. With this purpose, poly(ɛ-caprolactone)-poly(ethylene glycol)-poly(ɛ-caprolactone) (PCL-PEG-PCL, PCEC) triblock co-polymers with high molecular weight were synthesized by using PEG with a wide range of molecular weight (from 0.6 kg/mol to 35 kg/mol) as macroinitiators. PCEC copolymers exhibited tunable mechanical properties with an elastic modulus in the range 338–705 MPa and a degradation rate from 60% mass loss after 8 h to 70% mass loss after 23 days in accelerated tests, as well as excellent cytocompatibility and cell attachment after culture with mouse fibroblast L929 cells. The mechanisms responsible for these properties were ascertained by means of different techniques to ascertain the structure–property relationship in PCEC copolymers. Furthermore, it was shown that it is possible to manufacture PCEC scaffolds by 3D printing with excellent dimensional accuracy and controlled microporosity. This study provides a promising strategy to design, select, and fabricate copolymers with tunable mechanical properties and degradation rate for tissue engineering applications.

Accelerated annealing of fused filament fabricated (FFF) thermoplastics via an improved core–shell filament

Thermoplastic parts manufactured via fused filament fabrication (FFF) have limited strength and toughness compared to other types of polymer additive and subtractive manufacturing. Low strength results from poor interlayer adhesion, making FFF parts not suitable for most engineering applications. Post processing solutions, such as annealing, enable healing of these interlayers, thus approaching injection molded parts. Prior work demonstrated a core–shell polycarbonate (PC)—acrylonitrile butadiene styrene (ABS) structured dual material filament to provide thermo-structural stability during annealing of the ABS component; however, annealing was limited to relatively low temperatures (135 °C) and required long annealing times (72 h). In the current work, a PC copolymer with a higher glass transition temperature (173 °C) than conventional PC is processed along with an extrusion-grade ABS into a PC-ABS core–shell filament. This improved dual material filament was printed, annealed, and evaluated via Izod impact testing, ultimately yielding 83% of bulk annealed ABS z-direction strength at an accelerated annealing time (8 h) and higher annealing temperature (155—175 °C). A demonstration part is printed with the dual material filament and annealed at 155 °C for 8 h, resulting in excellent dimensional accuracy, and a ductile failure at 73% higher ultimate load compared to the brittle failure of an as-printed part. This work highlights that material selection and design of a bicomponent filament geometry can lead to parts printed with FFF, with increased strength compared to other post-processing techniques at reduced processing times.

Laser directed energy deposition/milling hybrid additive manufacturing of thin-walled GH4169 alloy: Effect of processing strategy on its microstructure and mechanical properties

Laser directed energy deposition (LDED)/milling hybrid manufacturing process was utilized to produce thin-walled GH4169 parts for the first time. The impact of processing strategy, including varied milling rounds and building heights, on the printability, microstructure, and mechanical properties of the GH4169 parts were investigated. Increasing the number of milling rounds within a certain height along the build direction reduced the distance between adjacent hybrid-processed interfaces. Base on a comparative study of the thermal histories of LDED and LDED/milling processes, it was found that the microstructure at the hybrid-processed interfaces experienced less heat accumulation and fewer heating/cooling cycles. Therefore, GH4169 parts after milling exhibited a lower proportion of the Laves phase area with refined sizes and greater interdendritic Nb segregation than those produced by LDED alone. With increased milling rounds, the ultimate tensile strength and yield strength of the thin-walled GH4169 part fabricated using the hybrid process increased from 777.0 MPa to 823.0 MPa and from 506.0 MPa to 538.0 MPa, respectively, while the elongation decreased from 35.1% to 27.2%. These effects can be attributed to an increase in milling round within a constant forming distance, resulting in higher stiffness of the fabricated thin-walled GH4169 part. Finally, a thin-walled GH4169 blade with excellent dimensional accuracy and surface finish was successfully produced using the LDED/milling hybrid process, demonstrating the potential applicability of this process to nickel-based alloys.

Prediction model and compensation method for curing shrinkage of inkjet 3D printing parts

Inkjet 3D printing has huge potential for applications in electronics printing, ceramic printing, and other fields, primarily due to the excellent dimensional accuracy of printed products, which is particularly important for device performance. However, in inkjet 3D printing, the fusion and solidification of droplets can cause the samples to shrink in various directions, resulting in a deviation from the designed target size, and subsequently affecting the performance of the part. In this study, the curing shrinkage behavior of parts in inkjet 3D printing is examined. First, a shrinkage model of the droplet element is established using the finite element method in accordance with the material parameters, and the linear shrinkage rates of different droplet groups are obtained. A curing shrinkage prediction model of the printed parts is then established, and the size and shape of the cured parts are predicted accordingly. A height calculation model of the printed parts is established according to the concept of volume conservation, and the height prediction of the printed parts is realized according to the number of printed layers and their resolution. An approach for compensation of the print model graphic layers is developed using the established prediction model. Experiments using two printing materials with different degrees of shrinkage are conducted to verify the feasibility of this method. The results indicate that the proposed curing shrinkage prediction model can seamlessly capture the curing shrinkage behavior of printed parts for materials with different shrinkages. Furthermore, after shrinkage, the model-based print compensation method achieves the measured sizes that are closer to the target size than that without compensation. The dimensions of inkjet 3D printed parts can be accurately controlled using this method.

The Modification of the Runner and Ingate Geometry to eliminate Misrun Defects on the Piston using Gravity Die Casting

Piston is an essential component of an engine because it plays a crucial role in the combustion process that drives the motorcycle. Gravity dies casting has become an ideal method for producing pistons owing to its high-quality product, cost-effective with excellent dimensional accuracy, good surface finish, and performance characteristics. However, misrun defect may occur during metal filling and solidification. This study aims to find the suitable dimensions for motorcycle piston products without the presence of misrun using MAGMASoft. The geometry modification introduced in this research are an ingate area of 176, 264, and 352 mm2 as well as the angle of runner of 60, 160, and 180o. Modifying the ingate area to 264 mm2 and the angle of the runner to 160o eliminated the misrun defect in the piston product. This phenomenon results from the laminar flow, higher temperature, and quicker flow velocity of the molten metal as it fills the window (the thinnest part of the piston).

Fabrication of 3D Printed Ceramic Part Using Photo-Polymerization Process.

Ceramics are high-strength and high-temperature resistant materials that are used in various functional parts. However, due to the high strength and brittleness properties, there are many difficulties in the fabrication of complex shapes. Therefore, there are many studies related to the fabrication of ceramic parts using 3D printing technology optimized for complex shapes. Among them, studies using photo-polymerization (PP) 3D printing technology with excellent dimensional accuracy and surface quality have received the most widespread attention. To secure the physical properties of sintered ceramic, the content and distribution of materials are important. This study suggests a novel 3D printing process based on a high-viscosity composite resin that maximizes the content of zirconia ceramics. For reliable printing, the developed 3D printers that can adjust the process environment were used. To minimize warpage and delamination, the divided micro square pattern images were irradiated in two separate intervals of 1.6 s each while maintaining the internal chamber temperature at 40 °C. This contributed to improved stability and density of the sintered structures. Ultimately, the ceramic parts with a Vickers hardness of 12.2 GPa and a relative density of over 95% were able to be fabricated based on a high-viscosity resin with 25,000 cps.

Preparation and Characterization of Poly(Acrylic Acid)-Based Self-Healing Hydrogel for 3D Shape Fabrication via Extrusion-Based 3D Printing.

The three-dimensional (3D) printing of hydrogel is an issue of interest in various applications to build optimized 3D structured devices beyond 2D-shaped conventional structures such as film or mesh. The materials design for the hydrogel, as well as the resulting rheological properties, largely affect its applicability in extrusion-based 3D printing. Here, we prepared a new poly(acrylic acid)-based self-healing hydrogel by controlling the hydrogel design factors based on a defined material design window in terms of rheological properties for application in extrusion-based 3D printing. The hydrogel is designed with a poly(acrylic acid) main chain with a 1.0 mol% covalent crosslinker and 2.0 mol% dynamic crosslinker, and is successfully prepared based on radical polymerization utilizing ammonium persulfate as a thermal initiator. With the prepared poly(acrylic acid)-based hydrogel, self-healing characteristics, rheological characteristics, and 3D printing applicability are deeply investigated. The hydrogel spontaneously heals mechanical damage within 30 min and exhibits appropriate rheological characteristics, including G'~1075 Pa and tan δ~0.12, for extrusion-based 3D printing. Upon application in 3D printing, various 3D structures of hydrogel were successfully fabricated without showing structural deformation during the 3D printing process. Furthermore, the 3D-printed hydrogel structures exhibited excellent dimensional accuracy of the printed shape compared to the designed 3D structure.

Manufacturing and Characterization of Dental Crowns Made of 5-mol% Yttria Stabilized Zirconia by Digital Light Processing.

We herein report manufacturing of dental crowns made of 5-mol% yttria partially stabilized zirconia (5Y-PSZ) with desired mechanical properties, optical translucency and dimensional accuracy using digital light processing (DLP). To this end, all processing parameters were carefully controlled and optimized. First, 5Y-PSZ particles with a bimodal distribution were prepared via calcination of as-received granules and subsequent ball-milling and then used to formulate 5Y-PSZ suspensions with a high solid loading of 50 vol% required for high densification after sintering. Dispersant content was also optimized. To provide high dimensional accuracy, initial dimensions of dental crowns for 3D printing were precisely determined by considering increase and decrease in dimensions during photopolymerization and sintering, respectively. Photopolymerization time was also optimized for a given layer thickness of 50 μm to ensure good bonding between layers. A multi-step debinding schedule with a slow heating rate was employed to avoid formation of any defects. After sintering at 1500 °C for 2 h, 5Y-PSZ could be almost fully densified without noticeable defects within layers and at interfaces between layers. They had high relative densities (99.03 ± 0.39%) with a high cubic phase content (59.1%). These characteristics allowed for achievement of reasonably high mechanical properties (flexural strength = 625.4 ± 75.5 MPa and Weibull modulus = 7.9) and % transmittance (31.4 ± 0.7%). In addition, 5Y-PSZ dental crowns showed excellent dimensional accuracy (root mean square (RMS) for marginal discrepancy = 44.4 ± 10.8 μm and RMS for internal gap = 22.8 ± 1.6 μm) evaluated by the 3D scanning technique.

Manufacturing and characterization of aa3003 aluminum alloy powders by synthesis of elementary powders by techniques of high energy ball milling

Manufacturing via powder metallurgy has several advantages such as high composition control, excellent dimensional accuracy, and good surface finish, among others, enabling the processing of different materials, including aluminum alloys, with wide application in diverse sectors of production. The present work aims to analyze the processing of an AA3003 aluminum alloy by the high energy ball milling technique (HEBM) under different production conditions. The particle size distribution of elementary and processed particulate was evaluated by laser diffraction. Elemental powders were processed by HEBM using milling intervals of 30, 60, and 120 minutes. The processed particulate materials were characterized by scanning electron microscopy (SEM), complementing the analysis with energy dispersive spectroscopy (EDS), in addition, the phases present were evaluated by X-ray diffraction (XRD). The characterization of the powders submitted to HEBM revealed that the increase in milling time contributed to the reduction of the average size of the particles, presenting an average diameter close to that verified in the particles of the base elements, Al and Mn.The best results found regarding the manufacture of the AA3003 alloy were found for samples obtained by milling time of 120 minutes, presenting as an effective processing interval to identify characteristic phases of the alloy.

Novel multi jet fusion 3D-printed patient immobilization for radiation therapy.

Thermoplastic immobilizers are used routinely in radiation therapy to achieve positioning accuracy. These devices are variable in quality as they are dependent on the skill of the human fabricator. We examine the potential multi jet fusion (MJF) 3D printing for the production immobilizers with a focus on the surface dosimetry of several MJF-printed PA12-based material candidates. Materials are compared with the goal of minimizing surface dose with comparison to standard thermoplastic. We introduce a novel metamaterial design for the shell of the immobilizer, with the aims of mechanical robustness and low-dose buildup. We demonstrate first examples of adult and pediatric cranial and head-and-neck immobilizers. Three different PA12 materials were examined and compared to fused deposition modeling-printed polylactic acid (PLA), PLA with density lowered by adding hollow glass microspheres, and to perforated or perforated/stretched and solid status quo thermoplastic samples. Build-up dose measurements were made using a parallel plate chamber. A metamaterial design was established based on a packed hexagonal geometry. Radiochromic film dosimetry was performed to determine the dependence of surface dose on the metamaterial design. Full cranial and head-and-neck prototype immobilizers were designed, printed, and assessed with regard to dimensional accuracy. Build-up dose measurements demonstrated the superiority of the PA12 material with a light fusing agent, which yielded a ∼15% dose reduction compared to other MJF materials. Metamaterial samples provided dose reductions ranging from 11% to 40% compared to stretched thermoplastic. MJF-printed immobilizers were produced reliably, demonstrated the versatility of digital design, and showed dimensional accuracy with 97% of sampled points within ±2mm. MJF is a promising technology for an automated fabrication of patient immobilizers. Material selection and metamaterial design can be leveraged to yield surface dose reduction of up to 40%. Immobilizer design is highly customizable, and the first examples of MJF-printed immobilizers demonstrate excellent dimensional accuracy.

Processing and mechanical properties of novel biodegradable poly-lactic acid/Zn 3D printed scaffolds for application in tissue regeneration

The feasibility to manufacture scaffolds of poly-lactic acid reinforced with Zn particles by fused filament fabrication is demonstrated for the first time. Filaments of 2.85 mm in diameter of PLA reinforced with different weight fractions of μm-sized Zn - 1 wt.% Mg alloy particles (in the range 3.5 to 17.5 wt.%) were manufactured by a double extrusion method in which standard extrusion is followed by precision extrusion in a filament-maker machine. Filaments with constant diameter, negligible porosity and a homogeneous reinforcement distribution were obtained for Zn weight fractions of up to 10.5%. It was found that the presence of Zn particles led to limited changes in the physico-chemical properties of the PLA that did not affect the window temperature for 3D printing nor the melt flow index. Thus, porous scaffolds could be manufactured by fused filament fabrication at 190 °C with poly-lactic acid/Zn composites containing 3.5 and 7 wt.% of Zn and at 170 °C when the Zn content was 10.5 wt.% with excellent dimensional accuracy and mechanical properties.

Crown fit and dimensional accuracy of zirconia fixed crowns based on the digital light processing technology

Zirconia is extensively used for manufacturing dental prostheses because of its superior mechanical properties. The idea of using 3D printing to manufacture zirconia dental prostheses has gradually become popular, but printing accurate shapes and obtaining excellent dimensional accuracy still remain challenging. In this study, the optimal curing parameters and shrinkage ratios of zirconia slurry were investigated using a multi-angle model and a standard fixed crown model. Then the dimensional accuracy and crown fit were investigated, and the fixed crown and fixed bridge were fabricated by using digital light processing (DLP) technology. Further, the dimensional accuracy and crown fit were investigated. The results showed that the optimal curing parameters and enlargement factors for zirconia fixed crown printing were 80 PWM (light source power), 2s (curing time) and 1.400, 1.400, 1.500 (in X, Y, Z directions), respectively. The internal fit was 239.3 ± 7.9 μm, which met the clinical criteria (≤300 μm), whereas the marginal fit was 128.1 ± 7.1 μm, which was extremely close to the clinical criteria (≤120 μm). For dimensional accuracy, the standard error of sintered fixed crown was 0.14 ± 0.06 mm, and the boundary dimensional accuracy and anatomical landmark points’ dimensional accuracy were also investigated. In addition, the density of sintered zirconia was 6.01 ± 0.02 g/cm 3. From the results of this study, it could be found that the crown fit of zirconia fixed crowns printed using the DLP technique could be close to clinical standards, although there is still a gap with the zirconia fixed crowns from the milling technique. In addition incomplete removal of the support structures have a negative impact on dimensional accuracy, hence it is necessary to further explore the optimization strategies of the support structures for improving the dimensional accuracy of fixed crowns printed by DLP.

Recent research development of CNC based milling machining conditions: A comprehensive review

With the advancement in manufacturing technologies, various improved machining processes have been developed and CNC based milling process is also one of the front line machining providing more advantages than another traditional process. With the substantial growth of machining processes, machining characteristics also change according to the tool and work materials, tools being used types of machining process utilized, etc. due to improved surface finish with excellent dimensional accuracy with minimum tool wear. In this context, these output parametersneed to get fulfilled by optimizing the input parameters like cutting speed, feed rate, and depth of cut during machining of the cutting environments like dry machining, flood cooling, Minimum Quantity Lubrication (MQL). Here some of the advanced cutting conditions based on CNC milling considering various types of materials are reviewed. This will assist researchers to focus on further exploring CNC based Milling process.

Comparative study of conventional and glass fiber modified ceramic shells

ABSTRACT Investment casting (IC) is well known to produced castings with excellent surface finish quality and close dimensional accuracy. Shell cracking is the foremost cause of casting rejection in the IC process. There are many causes of shell cracking in the IC process. However, the leading cause is poor shell strength. The shells having poor strength would produce defects on the final cast part and degraded the mechanical properties of the part. In this research work, the main objective was to improve ceramic shell strength by adding glass fibers to the backup coat ceramic slurry. It can be observed that the addition of glass fibers enhanced the flexural strength of the modified shell when compared to that of the conventional shell. The highest flexural strength was exhibited by the shell, which was modified with 0.50 wt.% of glass fibers. Fiber-reinforced modified ceramic shells had a larger bonded area between the fibers modified ceramic slurry and stucco coating. FE-SEM was used to analyze the microstructure characterization. Permeability and inner layer roughness of conventional and modified shells were measured and compared with conventional shells. XRD analysis was carried out with 0.50 wt.% of glass-fibers of unfired and fired shells at 700°C, 800°C & 900°C.

Additive manufacturing of novel 3D ceramic electrodes for high‐power‐density batteries

AbstractThe development of batteries with high‐specific power and energy densities will enable more efficient implementation of all‐electric aircraft and urban air mobility technologies. Additive manufacturing technologies can be leveraged to produce engineered three‐dimensional electrode structures with increased electrolyte/electrode interfacial area and high density, yielding increased power and energy densities. In this work, a novel engineered three‐dimensional interdigitated LiFePO4 cathode structure was designed and manufactured using direct‐write additive manufacturing technology, which allowed for the deposition of highly solid‐loaded inks with excellent dimensional accuracy. Ink rheology was adjusted to optimize material characteristics of the final electrodes, including the addition of carbon nanoparticles to increase the final electrode conductivity. Printed cathodes were then sintered and characterized. The sintered electrodes possessed greater structural stability and a surface area approximately 190% greater than similarly produced devices reported in the literature. Finally, the characterization of the manufactured electrodes showed uniform dispersion of conductive carbon nanopowder throughout the microstructure, which could increase the final conductivity of the electrodes.

Fabrication of Release Agent Supply Die with Porous Structure Using Metal-Based Additive Manufacturing

In powder bed fusion (PBF), a type of metal-based additive manufacturing (AM) process, metal powders are deposited on a substrate and melted through selective laser-beam irradiation. Among AM processes, PBF yields excellent dimensional accuracy, and the built parts can be applied to molding dies and topology-optimized parts. Furthermore, PBF can be used to build porous structures. In this study, a highly functional die casting method was established using PBF, which involved a release agent supplied through the porous structure to the surface of the proposed die. The arrangement of the porous structure made it possible to apply the release agent to the deep groove, which is not possible using a spray as in conventional supply methods. The laser-irradiated area was visualized to confirm pore formation, and the building conditions of the porous structure suitable to supply the release agent were investigated. The resulting die casting characteristics were evaluated. Considering the obtained results, guidelines to build dies or molds for die casting with porous structures are recommended. The amount of release agent could be controlled at each position of the die casting die, and the melted Al alloy did not penetrate the porous structure. In addition, the obtained Al alloy casting did not exhibit any castability defects. Moreover, suitable control of the supply of the release agent enabled enhancement of the die casting characteristics.

Dental zirconia fabricated by stereolithography: Accuracy, translucency and mechanical properties in different build orientations

Additive manufacturing (AM) zirconia shows excellent prospects for use in clinical applications. In this work, AM zirconia samples were fabricated in horizontal (H) and upright (U) fashion using a stereolithography appearance (SLA) system. The dimensional accuracy, density, translucency, surface quality, flexural strength and fracture toughness (KIc) of the samples were then assessed. AM zirconia fabricated in a H fashion shows excellent dimensional accuracy. Samples fabricated in a U fashion exhibit a higher density (relative density 95.4%) and translucency (4.393), but H group samples exhibit a higher KIc value (12.635 ± 1.372 MPa m1/2). The flexural strengths of the samples were measured and the values were compared according to their different build orientations, surface quality and fracture modes. Manual defects that arose in the samples as a result of their separation from the build platform in which they were made were found to lead to samples with irregular surface morphologies and increased surface roughness. However, this type of defect does not affect the flexural strength of samples fabricated in a H fashion. Polished-H samples that fracture from the stress concentration area exhibit the highest flexural strength (1151.08 ± 166.41 MPa) amongst all the samples prepared in this work. However, the flexural strength of the samples prepared in a U fashion is obviously low, even after polishing (225.44 ± 46.10 MPa). The Weibull characteristic strengths and Weibull moduli of the as-sintered samples are 920.22 MPa and 6.50 for H and 219.59 MPa and 7.99 for U, respectively. Overall, it was found that the dimensional accuracy, density, translucency, surface quality and mechanical properties of materials vary according to their different build orientations.