Pattern Casting Research Articles

The Utilization of Polyvinyl Alcohol (PVA) Filaments for the Three-Dimensional Printing of Water-Soluble Patterns for Investment Casting

In the domain of metal casting, investment casting is recognized for its proficiency in producing high-quality castings. This method involves the utilization of a melt out, burnout, or soluble patterns to create ceramic molds. The present investigation explored the potential of utilizing fused deposition modeling (FDM) patterns fabricated from polyvinyl alcohol (PVA). An examination of the structural characteristics and properties of several commercially available PVA filaments, along with an evaluation of the as-printed samples, were provided in this study. It was demonstrated that commercial PVA filaments may contain additives that can lead to elevated ash content following pattern burnout and reduced strength in as-printed samples. Experiments on PVA dissolution in water revealed that, for high dissolution rates of the pattern, not only high temperature, but also water medium mixing was necessary. The colloidal silica binder, a common component in ceramic mold manufacturing, exhibited effective wetting properties of the patterns, while generally preventing significant dissolution, which can adversely impact pattern quality. The PVA filaments under investigation were utilized to fabricate patterns for the impeller cast parts. Subsequent to this, ceramic molds were obtained, and castings made of nickel superalloy were produced. The investigation revealed that the Bambu Lab filament, which is PVA without additives, exhibited the lowest defect rate in both the mold and the casting. In summary, this study demonstrates that the 3D printing of investment casting patterns holds considerable promise as a rapid casting technique.

Evaluation of novel 3D printed foam patterns for rapid investment casting based on fused filament fabrication

Purpose This study aims to evaluate the effectiveness of three-dimensional (3D) printed foam polylactic acid (PLA) patterns in reducing ceramic shell stresses and cracking during burnout in the rapid investment casting (RIC) process to improve casting yield and dimensional tolerances. Design/methodology/approach Cylindrical and step-wedge patterns were 3D printed using foam PLA feedstock and compared with patterns from plain PLA and Polyvinyl Butyral (PVB). The patterns were shelled using ceramic slurry and investment cast in A356.1 aluminum alloy. Shell cracking and dimensional tolerances of resulting castings were assessed. Additionally, a complex component was 3D printed, laser-scanned, then cast and rescanned to evaluate dimensional accuracy. Finite Element Analysis (FEA) was conducted on cylindrical geometries to analyze internal mold pressure because of thermal stresses during burnout. Findings The foam PLA for all patterns produced no shell cracking during both ramp and flash burnouts. Castings made from foam PLA patterns showed improved dimensional tolerances and a narrower error distribution in GD&T analysis compared to those made from PLA and PVB. FEA results indicated that the thermomechanical properties of foam PLA reduce internal mold pressure by over 90%, which decreased internal shell stresses. Originality/value This research introduces a novel application of 3D printed foam PLA feedstock in the RIC process as a pattern material. This study demonstrates that foam PLA patterns effectively eliminate shell cracking during burnout and enhance dimensional accuracy. The findings of this study offer a new approach for improving dimensional tolerances and casting yield in RIC, which has not been previously explored.

Clinical internal and marginal fit of metal‐ceramic fixed dental prostheses fabricated with selective laser melting and 3D‐printed pattern casting using cobalt‐chromium metal alloy

AbstractPurposeTo evaluate the fit of metal–ceramic three‐unit fixed dental prostheses (FDPs) fabricated using selective laser melting (SLM) and 3D‐printed casting pattern (CP) and to compare the effect of tooth type and ceramic veneering on marginal and internal gaps.Materials and MethodsPatients requiring posterior three‐unit FDPs were selected. For each subject, two FDPs were fabricated using SLM and CP. Silicon replica was used to measure the internal and marginal fit of frameworks before and after ceramic veneering. For each replica, 36 measurements were performed using a stereomicroscope: 4 marginal and 32 internal (4 deep chamfers, 12 axial, 4 axio‐occlusal, and 12 occlusal). Statistical analysis was performed using two‐way ANOVA and paired t‐test.ResultsA total of 44 metal–ceramic FDPs were fabricated in 22 patients. The results showed that the fabrication method had no significant effect on the marginal, deep chamfer, or occlusal gaps. However, the method significantly affected the axial, axio‐occlusal, and total internal fit, and the SLM had larger gaps than the CP. For the effect of ceramic veneering, measurements were significantly higher in the CP group at all gaps, except for the premolar axial and molar occlusal gaps. The SLM fit was less affected by ceramic veneering. Only premolar gaps significantly increased at the marginal, deep chamfer, and axial and axio‐occlusal positions.ConclusionMetal–ceramic FDPs fabricated using SLM and CP techniques provided a similar marginal fit. Premolars had smaller discrepancies compared to molars. The ceramic veneering process increased the gap of the prostheses, with SLM being less affected by ceramic veneering.

Comparing the trueness of 3D printing and conventional casting for the fabrication of removable partial denture metal frameworks for patients with different palatal vault depths: An in vitro study

Statement of problemThe success of a removable partial denture depends on its fit, and, with conventional casting, the framework is more distorted in patients with a deep palatal vault. Questions remain about whether the three-dimensional (3D) printing technique for fabricating a framework can improve the accuracy of fit for these patients. PurposeThe purpose of this in vitro study was to compare the trueness of metal frameworks fabricated by selective laser melting, 3D printing pattern casting, and conventional casting for different palatal vault depths. Material and methodsA total of 30 partially edentulous maxillary casts were custom-made in 15 medium and 15 deep palatal vaults. All stone casts were scanned as reference models in digital files. For the medium palatal vault casts, Co-Cr frameworks of the conventional casting (CON) group (n=5) were fabricated with the lost wax technique. For the 3D printing pattern casting (PPC) group (n=5), wax patterns of the framework were printed, followed by metal casting. The frameworks created for the selective laser melting (SLM) group (n=5) were printed directly by using the SLM machine. The same procedures were followed for the deep palatal vault group. All the metal frameworks were scanned and superimposed with the reference casts by using the Geomagic Control X software program. Discrepancies were measured as mean ±standard deviation (trueness), and the data were statistically analyzed with a 2-way ANOVA test to evaluate the interaction of 2 independent factors (fabrication techniques and palatal vault depths) on a trueness outcome (α=.05). ResultsThe lowest mean ±standard deviation value was 0.092 ±0.023 mm, found from the SLM framework with deep palatal vault group, while the highest value was 0.194 ±0.017 mm, found from the CON framework with deep palatal vault group. Different fabrication techniques interacted with different palatal vault depths in terms of trueness (P<.05); however, no significant differences were observed in the medium palatal vault groups (P>.05). Additionally, color mapping demonstrated the gaps of metal frameworks among the 6 groups. ConclusionsWith the conventional casting technique, the accuracy of the metal framework was affected by the depth of the palate. For medium palatal vaults, all fabricated frameworks had clinically acceptable fit. For deep palatal vaults, the SLM frameworks showed the lowest discrepancy. As a result, the SLM technique is advised for fabricating a better-fitting metal framework for patients with a deep palatal vault.

Rapid Investment Casting: Towards Rapid Die Development

Abstract: Presently the cost of investment casting via wax patterns is an expensive endeavor. Its costs are only justified if the end product is to be produced in high volumes, however for customized products or small Industries, the costs are not viable. In Pakistan, die manufacturing is especially costly due to the use of modern computerized machines like CNC machining and electric discharge machining (EDM). The cost of manufacturing increases significantly with the complexity of the die, the number of cavities, high surface quality requirements, and the number of undercuts. The purpose of this research is to use modern techniques to investigate the feasibility of dies manufacturing through rapid investment casting technique. 3D printing technology is used to make the patterns for casting of die. The research focuses on the differences in dimensions between the actual casted die, and the designed values.

Build angle effect on 3D-printed dental crowns marginal fit using digital light-processing and stereo-lithography technology: an in vitro study

BackgroundThe effect of 3D printing technology and build angle on the marginal fit of printed crowns is unclear. The objective of this research was to use digital light processing (DLP) and stereo-lithography (SLA)-based 3D printing to construct single restorations with varied build angles and to analyze the crowns′ marginal fit.MethodsA prepared resin first molar was scanned utilizing an optical scanner. Three build orientations were used to construct the specimens: 0, 45, and 90º. DLP and SLA technology were used to produce the casting patterns. A digital microscope was used to measure the marginal gaps. The effect of build orientation was statistically analyzed by using Two-way ANOVA followed by pair-wise Tukey test.ResultsTwo-way ANOVA revealed a significant effect of printer technology and build angle on the marginal discrepancy of 3D printed crowns (p < 0.001). One-way ANOVA revealed that SLA printers (55.6 [± 13.59]) showed significantly better mean [± SD] marginal discrepancy in µm than DLP printers (72 [± 13.67]) (p < 0.001). Regarding build angle, one-way ANOVA revealed significant differences between the different angles. Tukeys post-hoc test revealed that 0° (48.5 [± 9.04]) had the significantly smallest marginal discrepancy followed by 45° (62.5 [± 8.05]) then 90° (80.5 [± 8.99]) (p < 0.001).ConclusionThe build orientation affects the marginal discrepancy of single crowns manufactured utilizing DLP and SLA.

Optimization of Dimensional Accuracy and Surface Roughness of SLA Patterns and SLA-Based IC Components.

Rapid investment casting is a casting process in which the sacrificial patterns are fabricated using additive manufacturing techniques, making the creation of advanced designs possible. One of the popular 3D printing methods applied in rapid investment casting is stereolithography because of its high dimensional precision and surface quality. Printing parameters of the used additive manufacturing method can influence the surface quality and accuracy of the rapid investment cast geometries. Hence, this study aims to investigate the effect of stereolithography printing parameters on the dimensional accuracy and surface roughness of printed patterns and investment cast parts. Castable wax material was used to print the sacrificial patterns for casting. A small-scale prosthetic biomedical implant for total hip replacement was selected to be the benchmark model due to its practical significance. The main results indicate that the most significant stereolithography printing parameter affecting surface roughness is build angle, followed by layer thickness. The optimum parameters that minimize the surface roughness are 0.025 mm layer thickness, 0° build angle, 1.0 support density index, and across the front base orientation. As for the dimensional accuracy, the optimum stereolithography parameters are 0.025 mm layer thickness, 30° build angle, 0.6 support density index, and diagonal to the front base orientation. The optimal printing parameters to obtain superior dimensional accuracy of the cast parts are 0.05 mm layer thickness, 45° build angle, 0.8 support density index, and diagonal to the front model base orientation. With respect to the surface roughness, lower values were obtained at 0.025 mm layer thickness, 0° build angle, 1.0 support density index, and parallel to the front base orientation.

Porous wax patterns for high-precision investment casting

Aerospace, manufacturing, and shipbuilding industries strive to enhance their competitiveness by optimizing material utilization and improving production processes. The investment casting process offers the capability to fabricate intricate and precise components using a diverse range of alloys. However, this method is not without its drawbacks, including high manufacturing costs and a significant rate of defective castings, which can reach up to 30 %. These defects primarily arise from the stresses imposed on the wax patterns and ceramic molds, leading to their distortion. To address this issue, efforts have been made to reduce stress by employing compacted wax powders for the production of investment patterns. However, stress relaxation in the wax patterns remains a concern as it can result in elastic deformation of the compacted material and subsequent alterations in the final product dimensions. To mitigate this issue, a series of tests were conducted with the objective of studying stress relaxation under constant compression strain, as described by the Kohlrausch equation. The obtained results provide valuable insights that enable the prediction of the ultimate dimensions of patterns created using different grades of wax.

Experimental and Simulation Investigation on Energy Absorption of Cu Casting Lattice Structure during Compression

This investigation aims to assess the mechanical behavior and energy absorption properties of the Cu lattice structures made by investment casting method experimentally and by finite element method (FEM) simulation. The casting pattern of lattice structures is additively manufactured with 2.0, 2.5, and 3.0 mm diameters and the lattice structures produced by investment casting of Cu. Then a uniaxial compression test is applied to measure maximum compressive strength, energy absorption density, efficiency, and specific energy absorption. The simulation and the experimental results indicate that the abovementioned properties of the lattice structures have a significant improvement and properties developments will rise by increasing the diameter of the struts. The mechanical characterization has done for Cu lattice structure with 3.0 mm strut diameter, which endures a stress of 242 MPa at the densification strain and the maximum tolerated stress of 404 MPa. The energy absorption density of this lattice structure is 67 MJ m−3 and has a specific energy absorption of 28 J g−1 followed by an energy absorption efficiency around 70%. The simulation result shows a mathematical connection between the unit cells and the final lattice structures in terms of maximum tolerated stresses, which can help the prediction of the mechanical behavior of these structures.

Evaluation of marginal accuracy of nickel chromium copings fabricated from three different fabrication techniques: an in vitro study

The purpose of the study was to compare the marginal accuracy of Ni-Cr copings made by four different pattern forming methods, using inlay casting wax and pattern resin in the conventional manner, inlay wax patterns by CAD &amp; milling and resin patterns made by a 3 dimensional printing (3DP) technology a total of 40 test samples of Ni-Cr cast copings were made out of 10 patterns of each group using inlay casting wax, pattern resin, inlay wax by CAD and milling and from pattern resin by 3D printing technology. Each cast coping was seated on the stainless steel die and was evaluated for both vertical and horizontal marginal gaps using a translating tool makers microscope. The vertical marginal gap data was analyzed by use of Kruskal Wallis Test followed by Mann Whitney U Test and the horizontal marginal gap data was analyzed by using ANOVA followed by Tukey honestly significantly different (HSD) tests. 3D printed resin pattern copings showed better results of marginal adaptability. marginal fit of the Ni-Cr cast copings fabricated from the patterns prepared from inlay casting wax, pattern resin, CAD milling and 3 dimensional printing (3DP) technology were in the clinically acceptable range for longevity of restorations.

AN IN VITRO COMPARISON OF OVERALL FIT OF COBALT-CHROMIUM COPINGS CASTED CONVENTIONALLY FROM INLAY CASTING WAX, PATTERN RESIN &amp; 3D PRINTED RESIN EVALUATED BEFORE &amp; AFTER CERAMIC FIRING CYCLES

Aim: To compare the overall fit of cobalt-chromium copings casted conventionally from inlay casting wax, auto polymerizing pattern resin &amp; 3D printed resin evaluated before &amp; after ceramic firing cycles. Method: A stainless-steel master die assembly was fabricated which was used to fabricate the working models. 60 working dies (Group A Inlay Casting Wax n=20, Group B Pattern Resin n=20, Group C 3D Printed Resin n=20) simulating full crown preparations werestudied. The stainless-steel master die was duplicated using polyvinyl siloxane (PVS) elastomeric impression and poured in gypsum type IV die stone. Dieswere scanned using a digital scanner. 60 cobalt-chromium (Co-Cr) metal copings were fabricated using three different techniques: inlay casting wax, autopolymerising pattern resin&amp; 3D printed resin. Each die was fired with conventional PFM ceramic. A standardized weightwas used to exert uniform pressure on the elastomeric impression material while recording the intaglio surface of the crowns (copings) fabricated before and after ceramic firings. It was thenscanned aiding in STL File. The STL files were later overlapped and evaluated on their respective working die STL file using the software. The overall fit was measured by colour surface mapping software viz before &amp; after ceramic firing cycles. Results: The copings obtained by 3D printed resin technique revealed the best overall fit before and after ceramic firing cycles amongst the three fabrication techniques. Conclusion: 3D printed resin technique had the best overall fit before and after ceramic firing cycles followed by inlay casting wax technique and pattern resin technique.

Thermal, mechanical and rheology of EVA/wax and wax/LLDPE blends as a carrier vehicle for investment casting pattern

ABSTRACT Different ratios of wax/ethylene vinyl acetate (EVA) and wax/linear low-density polyethylene (LLDPE) blends were prepared using one-step extrusion process to investigate their potential as carrier vehicles for pattern material for investment casting. The thermal, mechanical and rheological properties were characterised. Thermal analysis was done by thermogravimetric analysis (TGA) and differential scanning calorimetry. Mechanical properties were characterised by three-point bending and thermomechanical analysis, whereas the rheological properties were characterised by oscillatory rheometry. The TGA analysis showed that the incorporation of EVA or LLDPE into wax matrix improved the thermal stability properties of the blend. This can be attributed to an enhanced phase adhesion. The melting and solidification behaviour of the blends had intermediate temperatures between wax and EVA. The EVA/wax blends displayed evident viscosity shifts as compared to the viscosity of wax. The incorporation of EVA into wax significantly altered its mechanical properties. Fourier transform infrared spectrometry for both wax/EVA and wax/LLDPE showed a predominant presence of CH2 and carbonyl group in the blend, and the mechanical properties of neat wax were improved when EVA and LLDPE were incorporated into wax.

Flexible Investment Casting Wax Patterns for 3D-Printing: Their Rheological and Mechanical Characterizations.

The mechanical and rheological characterizations of flexible investment casting patterns capable of 3D printing are reported. The wax pattern was composed of microcrystalline hydrocarbon wax (DMW7478), Piccotex 75 (a copolymer of α-methyl-styrene and vinyl toluene with a 75/25 molar ratio, respectively) and Escorene (a copolymer of ethylene and vinyl acetate with a 72/28 mass ratio, respectively). It was found that in order to obtain a wax pattern with appreciable mechanical properties, the content of the microcrystalline hydrocarbon wax in these blends should not exceed 30% (m/m). Thus, a series of patterns with 28% (m/m) wax and varying Piccotex and Escorene contents spanning from 0 to 72% (m/m) was prepared. The dependence of the dynamic viscosities of the wax patterns on the composition was described using a stretched exponential model, whereas their variations with the temperature were interpreted in terms of the Arrhenius-Guzman equation. Furthermore, the slopes of the lines fitted to the viscosity versus temperature curves at the pour point decreased linearly with the Piccotex content. Non-Newtonian changes in the shear stress with the shear rate and shear stress crystallization were observed at temperatures near the pour points. The mechanical properties were evaluated using the uniaxial tensile mode and by three-point bending experiments. It was found that the stress (σ) versus the relative elongation (ε) curves can effectively be rendered by means of the standard linear solid (SLS) viscoelastic model. In addition, it was also established that the Young's modulus varied according to a sigmoid-type curve with the piccotex content, while the yield stress decreased linearly with the concentration of Piccotex. In addition, based on the spooling suitability and printability, the patterns were rated and it was found that the most appropriate wax pattern compositions for 3D printing were those which contained 30% (m/m) and 35% (m/m) Piccotex.

Large Scale Vat-Photopolymerization of Investment Casting Master Patterns: The Total Solution.

The material properties and processing of investment casting patterns manufactured using conventional wax injection Molding and those manufactured by vat photopolymerization can be substantially different in terms of thermal expansion and mechanical properties, which can generate problems with dimensional accuracy and stability before and during ceramic shelling and shell failures during the burn-out of the 3D printed casting patterns. In this paper and for the first time, the monofunctional Acryloyl morpholine monomer was used for 3D printing of casting patterns, due to its thermoplastic-like behavior, e.g., softening by heat. However, the hydrophilic behavior of this polymer led to an incorporation of up to 60 wt% of Hexanediol diacrylate, to control the water absorption of the network, which to some extent, compromised the softening feature of Acryloyl morpholine. Addition of a powdered wax filler resulted in a delayed thermal decomposition of the polymer network, however, it helped to reduce the thermal expansion of the parts. The dimensional accuracy and stability of the wax-filled formulation indicated an excellent dimensional tolerance of less than ±130 µm. Finally, the 3D printed patterns successfully went through a burn out process with no damages to the ceramic shell.

Accuracy of Models Fabricated by a Chair-side Fused Deposition Modeling (FDM) Printer in Stomatology.

To establish a method to improve the accuracy of a dental chair-side fused deposition modelling (FDM) printer and assess the internal adaptation of full crown casting patterns produced by the FDM printer. A Lingtong dental three-dimensional (3D) printer (Beijing SHINO Company, China), was used to fabricate six cubes. Deviation analysis was performed between the 3D scanned data and the designed cube data. Fifteen crowns (Group LT) of the right maxillary first molar were printed. A DDP 3D printer (Group EV) and a milling machine (Group ZT) were used to produce the same crowns as controls. Compared with the designed cube, the 3D deviation of 73.75% points was within 0.1 mm. The calibration parameters (CP) of the X, Y, and Z directions were 1.005, 0.998, and 1.000, respectively. Based on the CP, the X and Y directions of the printer were adjusted in the software to compensate for the mechanical errors. The crowns were fabricated using different types of equipment to evaluate the accuracy of printing by the 3D dental printer. The internal gap of each crown was measured using a silicone replica and the 3D analysing method. In Group LT, the internal gap of the marginal, axial, and occlusal areas were 0.030 ± 0.019, 0.092 ± 0.019, and 0.023 ± 0.009 mm, respectively. In the marginal and occlusal areas, Group EV exhibited the smallest internal discrepancy, whereas in the axial area, Group ZT achieved the smallest. Only LT and ZT achieved internal spaces in the marginal area without statistical significance to the prescribed parameters (p>0.05). The crown cannot be placed on the preparation if the printer is not calibrated. This study revealed the inability to produce full crown casting patterns with similar internal adaptations using different machines for fabrication. None of the three groups could reproduce the prescribed internal space. Combined with CAD/CAM technology, 3D printing technology has been gradually applied in stomatology.

건축 파사드의 디지털 패턴 디자인 유형에 대한 감성 특성 - 밴 팰(Ben Pell)의 파사드 패턴 유형을 중심으로 -

Pattern is a visually important element in designing an architectural facade. The digital pattern design such as a facade is deeply related to aesthetic characteristics in architecture and interior design. However, the lack of research on a systematic design process for digitalized pattern design such a facade, poses a problem for designers. This research provides emotional characteristics on five types of architectural facade pattern: applied, perforated, layered, cast, and tiled. The analysis is based on an existing study that briefly analyzed their emotional characteristics, and this is combined with the results of other research on emotional characteristics of applied and perforated patterns. First, reviewing previous research reveals the reasons for selecting façade pattern types classified by Ben Pell and determines their classification criteria, the definitions, the general characteristics and the representative projects of the five types of architectural facade. Second, the survey method from existing research is used to establish targets, method, and analysis. Third, general information of survey respondents is analyzed in terms of gender, age, education, occupation, and experience. Results represent emotional characteristics by case and by type of digital pattern design of architectural facade and reveal a correlation between determined emotional characteristics by type and by case. After deriving their correlations, this study finally determines the emotional characteristics by type and case. Emotional responses are then presented by type and case. Fourth, the results are compared and analyzed with those of existing research. The results in the emotional characteristics show that the applied and layered patterns are continuous and discontinuous-continuous, respectively, the perforated pattern is irregular and irregular-regular, and the cast and tiled patterns are regular and irregular-regular, respectively. In the comparison of the average value by facade pattern design type, based on the results and as a design concept, a continuous continuity is more suitable for the layered pattern than the applied pattern, a regular regularity is more appreciated for the cast pattern than the tiled pattern, and an irregular regularity is good for designing the perforated pattern.

Process Parameter Optimization for 3D Printed Investment Casting Wax Pattern and Its Post-Processing Technique

This research paper aims to improve the quality of 3D printed parts made of the wax filament by implementing the Taguchi orthogonal array process optimization method. The manufactured parts can be used as cost-effective investment casting patterns. With the Taguchi method, it was concluded that the nozzle temperature has the most effect on the dimensional accuracy of printed parts. In addition, thermal, mechanical, and rheological characterization were performed on the wax filament, revealing several important findings. For instance, the rheological studies identified the low viscosity of melted wax at printing temperatures. This resulted in the rough surface of the printed parts. To improve the surface roughness, a post-processing procedure was implemented using a white spirit as a surface smoothing agent.

Effect of Palatal Vault Depth on the Trueness of Metal Laser-Sintered and Cast Cobalt-Chromium Removable Partial Denture Frameworks.

This in vitro study compared the trueness of removable partial denture cobalt-chromium (Co-Cr) frameworks fabricated by 3D-printed pattern casting and those fabricated by selective laser sintering (SLS) with different palate vault depths. A partially edentulous Kennedy class II mod.1 maxillary model with a deep palatal vault was used, which was modified and duplicated to produce another model with medium palatal vault depth. After model scanning, the partial denture framework was designed using CAD software to fabricate 20 removable partial denture (RPD) frameworks. For each model, two types of frameworks were fabricated. For the 1st type, the 3D-printed resin patterns were formed using a 3D printer, and then casting was performed (AM-cast framework). For the 2nd type, a direct metal laser sintering machine was used for the RPD frameworks fabrication (SLS framework). 3D scanning of fabricated frameworks was performed, and the standard tessellation language (STL) file was superimposed over the STL file from the original design, and the average deviation was recorded. Data were statistically analyzed. Two-way ANOVA test was used, followed by the least significant difference (LSD) for pair-wise comparisons to estimate any significant differences between groups. The RPD frameworks with high palatal vault depth represent larger discrepancies mean value than that with the medium palatal vault depth with a highly significant statistical difference. SLS shows less deviation than AM-cast CO-Cr frameworks with highly significant statistical differences whatever palatal vault depth. RPD metal frameworks fabricated with SLS have better accuracy compared to those fabricated by AM-cast, regardless of the depth of the palatal vault.

Role of Additive Manufacturing in Investment Casting Process

Abstract: The aim of this study was to describe systematically the best available evidence of Additive manufacturing (AM) technology for different casting paths and How Rapid Investment casting (RIC) is revolutionizing the field of casting. The objective of this systematic review is to investigate the capabilities and effectiveness of Additive Manufacturing to provide an effective solution for investment casting production. Google Scholar, ResearchGate, Mendeley, ScienceDirect databases are used for research purposes. The conventional method of Investment Casting is less effective in terms of cost and time to develop new hard tooling wax patterns for low volume production and prototypes. To overcome this problem, we introduced additive manufacturing for making patterns for investment casting. This paper reviews the specific applications of Rapid prototyping in the field of casting. After applying the inclusion criteria, we found 40 articles for reviewing. This study concluded that using Additive manufacturing in Investment casting in place of the conventional method is more cost- effective and time-efficient. Keywords: Additive Manufacturing, Rapid Investment Casting.

PENGARUH TEMPERATUR TUANG TERHADAP POROSITAS, STUKTUR MIKRO DAN KEKERASAN DARI ALUMUNIUM WAJAN NAGARA DAN WAJAN JAWA MENGGUNAKAN PENGECORAN EVAPORATIF

Aluminum and its alloys are the second largest metal materials used after steel. Applications and aluminum alloys are very diverse ranging from building vehicle bodies engine components components to ships to applications on airplanes. The strength and hardness of high aluminum alloys,one of the applications of aluminum as a component in the motor is as an ingredient for making alloy wheels, more specifically aluminum alloys. Used aluminum can be obtained from the remnants of the industry making aluminum doors, windows and frames, making aluminum shelves and storefronts, and other products with aluminum profiles as the main material. many of them use aluminum scrap as their main casting material to reduce production costs. Evaporative or casting casting using Styrofoam or a lost foam casting pattern is a casting using a material pattern that can evaporate when exposed to molten metal heat. Casting uses a temperature of 650 ° C, 700 ° C, 750 ° C, 800 ° C. The results of casting temperatures can affect porosity, microstructure, and hardness.