Narimasa Ueda, Akane Ishizuka, Y. Morimoto, Akio Hayashi, Y. Kaneko, Naohiko Suzuki
A machining center is a common machine tool that can machine complex free-form surfaces such as the press mold, automobile’s cam profile. When these curved surfaces are machined by the conventional machining center and/or the grinding machine, it takes lot of time to complete with enough accuracy. In order to solve this problem, this study aims not only to improve the machining accuracy of this curved surface but also to make it possible to shorten the machining time using a CNC lathe. In this study, the NACS-Turning (Non-axisymmetric curved surface turning) method that we proposed originally was used. In this study, the spindle of C-axis, the moving table with the cutting tool of X1-axis, the other counter moving table of X2-axis, the spindle feed table of Z-axis, and the tool rotation axis of B axis are adapted. In this 5-axis machining method, all the axis are controlled with the synchronized manner. This method can machine the same rotational position of workpiece with the same cutting edge of the rotary tool. As an experiment, we compared 5-axis machining with synchronized spindle and tool rotation, 4-axis machining, and machining with non-synchronous rotation. Our new 5-axis machining method with synchronized spindle and tool rotation reduced the form error from 387μm to 360μm and the surface roughness from Rz 9.6μm to Rz 4.7μm compared to 4-axis. In 5-axis machining with synchronizing the spindle and the tool rotation, the surface roughness was reduced from Rz 15.9μm to Rz 4.7μm compared to the non-synchronous machining.
加工中心是一种可以加工冲压模具、汽车凸轮轮廓等复杂自由曲面的通用机床。当这些曲面由传统的加工中心和/或磨床加工时，需要花费大量的时间才能完成足够的精度。为了解决这一问题，本研究不仅旨在提高该曲面的加工精度，而且可以缩短CNC车床的加工时间。本研究采用我们最初提出的非轴对称曲面车削(NACS-Turning, non -轴对称曲面车削)方法。本研究采用c轴主轴、带刀具的x1轴移动工作台、另一副x2轴移动工作台、z轴主轴进给工作台、B轴刀具旋转轴。在这种五轴加工方法中，所有的轴都是同步控制的。该方法可以用旋转刀具的同一切削刃加工同一旋转位置的工件。作为实验，我们比较了主轴和刀具同步旋转的五轴加工、四轴加工和非同步旋转的加工。采用主轴与刀具同步旋转的五轴联动加工方法，与四轴联动加工相比，工件的形状误差从387μm减小到360μm，表面粗糙度从9.6μm减小到4.7μm。在主轴与刀具同步旋转的5轴加工中，与非同步加工相比，表面粗糙度从15.9μm降低到4.7μm。
{"title":"A Study on 5-Axis Turning for Non-Axisymmetric 3D Surfaces","authors":"Narimasa Ueda, Akane Ishizuka, Y. Morimoto, Akio Hayashi, Y. Kaneko, Naohiko Suzuki","doi":"10.1115/imece2022-94885","DOIUrl":"https://doi.org/10.1115/imece2022-94885","url":null,"abstract":"\u0000 A machining center is a common machine tool that can machine complex free-form surfaces such as the press mold, automobile’s cam profile. When these curved surfaces are machined by the conventional machining center and/or the grinding machine, it takes lot of time to complete with enough accuracy. In order to solve this problem, this study aims not only to improve the machining accuracy of this curved surface but also to make it possible to shorten the machining time using a CNC lathe. In this study, the NACS-Turning (Non-axisymmetric curved surface turning) method that we proposed originally was used. In this study, the spindle of C-axis, the moving table with the cutting tool of X1-axis, the other counter moving table of X2-axis, the spindle feed table of Z-axis, and the tool rotation axis of B axis are adapted. In this 5-axis machining method, all the axis are controlled with the synchronized manner. This method can machine the same rotational position of workpiece with the same cutting edge of the rotary tool. As an experiment, we compared 5-axis machining with synchronized spindle and tool rotation, 4-axis machining, and machining with non-synchronous rotation. Our new 5-axis machining method with synchronized spindle and tool rotation reduced the form error from 387μm to 360μm and the surface roughness from Rz 9.6μm to Rz 4.7μm compared to 4-axis. In 5-axis machining with synchronizing the spindle and the tool rotation, the surface roughness was reduced from Rz 15.9μm to Rz 4.7μm compared to the non-synchronous machining.","PeriodicalId":141381,"journal":{"name":"Volume 2A: Advanced Manufacturing","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125734097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this project, we would like to explore the viability of using 3D printed injection molds to cost-effectively produce low-volume production runs. These 3D printed molds are much more cost-effective than traditional methods, however, the 3D printed molds often only withstand 50–100 cycles. Research is needed to determine how to improve the durability of the molds. This can be accomplished by measuring and documenting how injection molds made from various plastics, and various 3D printing technologies, react under the stresses of an injection molding machine. We can develop a case study using 4 different types of plastics that can be used to create the 3D printed mold. The 3 plastics would be Formlabs Ridged 10k Resin, Formlabs Clear v4, and Formlabs Tough 2000 Resin. These materials will be printed using various 3D printing technologies. This paper will focus on a literature review of the positives and negatives of 3D printing additively manufactured injection molding tooling and propose potential solutions for many of the negatives of 3D printed molds. The case study portion will be based on how we are planning to perform the case study, but it has not yet been completed.
{"title":"Design and Implement an Additive Manufacturing Injection Mold","authors":"Basel Alsayyed, Nicholas Foland","doi":"10.1115/imece2022-88593","DOIUrl":"https://doi.org/10.1115/imece2022-88593","url":null,"abstract":"\u0000 In this project, we would like to explore the viability of using 3D printed injection molds to cost-effectively produce low-volume production runs. These 3D printed molds are much more cost-effective than traditional methods, however, the 3D printed molds often only withstand 50–100 cycles. Research is needed to determine how to improve the durability of the molds. This can be accomplished by measuring and documenting how injection molds made from various plastics, and various 3D printing technologies, react under the stresses of an injection molding machine. We can develop a case study using 4 different types of plastics that can be used to create the 3D printed mold. The 3 plastics would be Formlabs Ridged 10k Resin, Formlabs Clear v4, and Formlabs Tough 2000 Resin. These materials will be printed using various 3D printing technologies. This paper will focus on a literature review of the positives and negatives of 3D printing additively manufactured injection molding tooling and propose potential solutions for many of the negatives of 3D printed molds. The case study portion will be based on how we are planning to perform the case study, but it has not yet been completed.","PeriodicalId":141381,"journal":{"name":"Volume 2A: Advanced Manufacturing","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133533565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study investigates the effect of autoclave curing variables on the glass transition temperature of and the degree of cure and strength of epoxy film adhesive single lap joints (SLJs) under static tensile shear loading. Studied autoclave variables include the cure temperature, cure pressure, temperature, and pressure ramp rates on the glass transition temperature as well as the cure time duration. Test joints are made of Aluminum substrates that are autoclave-bonded using epoxy film adhesive (AF163-2k). For each variable combination of the autoclave process, the corresponding glass transition temperature of cured Epoxy film adhesive is obtained using Dynamic Mechanical Analysis (DMA-Q800). Test data are generated for both baseline joints [uncycled] as well as for joints that have been heat-cycled in an environmental chamber after initial autoclave bonding. Results show a strong correlation between the autoclave process variable combinations and the corresponding glass transition temperature bond strength, and the failure mode of test joints.
{"title":"Effect of Autoclave Cure Temperature, Pressure, and Time on the Glass Transition Temperature and the Degree of Cure of Epoxy Film Adhesive Joints","authors":"S. Nassar, S. Jagatap, N. Hirulkar","doi":"10.1115/imece2022-94434","DOIUrl":"https://doi.org/10.1115/imece2022-94434","url":null,"abstract":"\u0000 This study investigates the effect of autoclave curing variables on the glass transition temperature of and the degree of cure and strength of epoxy film adhesive single lap joints (SLJs) under static tensile shear loading. Studied autoclave variables include the cure temperature, cure pressure, temperature, and pressure ramp rates on the glass transition temperature as well as the cure time duration. Test joints are made of Aluminum substrates that are autoclave-bonded using epoxy film adhesive (AF163-2k). For each variable combination of the autoclave process, the corresponding glass transition temperature of cured Epoxy film adhesive is obtained using Dynamic Mechanical Analysis (DMA-Q800). Test data are generated for both baseline joints [uncycled] as well as for joints that have been heat-cycled in an environmental chamber after initial autoclave bonding. Results show a strong correlation between the autoclave process variable combinations and the corresponding glass transition temperature bond strength, and the failure mode of test joints.","PeriodicalId":141381,"journal":{"name":"Volume 2A: Advanced Manufacturing","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133092148","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Material extrusion processes such as fused filament fabrication (FFF) are among the most widely used additive manufacturing (AM) technologies. The fused filament fabrication process consists of simultaneously feeding and melting a filament of polymer material through a computer-controlled liquefier. The material then flows through the nozzle under pressure, which must fully solidify while remaining in extruded shape. Deposited layers are fused together as the melted material quickly solidifies to form layers of a solid 3-D object. The key elements are material feed mechanism, liquefier, print nozzle, build surface and environment. The general applications are production of prototypes during product development phase, short series production runs where tooling cost is high, and parts with high geometrical complexity which cannot be produced by means of conventional manufacturing. Often, time evolution of temperature as recorded by thermography and adhesion behavior of filament are investigated by considering main process parameters, such as filament dimensions and material, sequence of deposition and environment temperature. In this paper, thermal behavior of material extrusion and filament adhesion is analyzed.
{"title":"Physics-Based Filament Adhesion Modeling in Fused Filament Fabrication","authors":"Shreyas Aniyambeth, Deepak Malekar, T. Özel","doi":"10.1115/imece2022-96486","DOIUrl":"https://doi.org/10.1115/imece2022-96486","url":null,"abstract":"\u0000 Material extrusion processes such as fused filament fabrication (FFF) are among the most widely used additive manufacturing (AM) technologies. The fused filament fabrication process consists of simultaneously feeding and melting a filament of polymer material through a computer-controlled liquefier. The material then flows through the nozzle under pressure, which must fully solidify while remaining in extruded shape. Deposited layers are fused together as the melted material quickly solidifies to form layers of a solid 3-D object. The key elements are material feed mechanism, liquefier, print nozzle, build surface and environment. The general applications are production of prototypes during product development phase, short series production runs where tooling cost is high, and parts with high geometrical complexity which cannot be produced by means of conventional manufacturing. Often, time evolution of temperature as recorded by thermography and adhesion behavior of filament are investigated by considering main process parameters, such as filament dimensions and material, sequence of deposition and environment temperature. In this paper, thermal behavior of material extrusion and filament adhesion is analyzed.","PeriodicalId":141381,"journal":{"name":"Volume 2A: Advanced Manufacturing","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132330083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Additive manufacturing has given a way to manufacture complex-shaped ceramic parts, which is impossible with conventional manufacturing methods. This paper demonstrated stereolithography printing and sintering of Silicon Carbide (SiC) ceramics via oxidation-bonding. The commercially available SiC powder and the photopolymer resins were utilized for stereolithography printing. Experiments were designed to study the effect of printing process parameters with the increase in SiC powder loading for the photopolymer slurry. It was observed that the curing time increased drastically with SiC powder loading. The SiC green parts were sintered at 1200°C in the air. The SEM-EDS analysis of sintered parts showed evidence of bonding the SiC particles via oxidation. This study paves the way for additive manufacturing of high-density and high-strength SiC/Silica composites.
{"title":"Stereolithography Printing and Sintering of Silicon Carbide (SiC) Ceramics via Oxidation-Bonding","authors":"Padmalatha Kakanuru, K. Pochiraju","doi":"10.1115/imece2022-96009","DOIUrl":"https://doi.org/10.1115/imece2022-96009","url":null,"abstract":"\u0000 Additive manufacturing has given a way to manufacture complex-shaped ceramic parts, which is impossible with conventional manufacturing methods. This paper demonstrated stereolithography printing and sintering of Silicon Carbide (SiC) ceramics via oxidation-bonding. The commercially available SiC powder and the photopolymer resins were utilized for stereolithography printing. Experiments were designed to study the effect of printing process parameters with the increase in SiC powder loading for the photopolymer slurry. It was observed that the curing time increased drastically with SiC powder loading. The SiC green parts were sintered at 1200°C in the air. The SEM-EDS analysis of sintered parts showed evidence of bonding the SiC particles via oxidation. This study paves the way for additive manufacturing of high-density and high-strength SiC/Silica composites.","PeriodicalId":141381,"journal":{"name":"Volume 2A: Advanced Manufacturing","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121978995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Suleiman Obeidat, Junkun Ma, Sophie Himelstein, Aniruddha Acharya
Additive manufacturing has been used extensively for the last decade in making different parts of different complexities. One of the additive manufacturing methods discussed in this work is binder jetting additive manufacturing (BJAM) process where a liquid-based binder is deposited on the powder bed to make the part layer by layer. In this work, ceramics particles are used to investigate the effect of the part geometry on the density and shrinkage of the part made. Three different shapes (spheres, cylinders, and rectangular blocks) of the same size are printed at 100%, 75% core saturation limit at zero second and 10-seconds delay using a binder jetting 3D printer at 0.2 mm layer thickness. The green parts are de-powdered and dried for 6–8 hours using a drying heater at 35° C then de-bound and sintered to improve the strength and the density of the part made. We use ceramics powder of particle size range 50–200 μm to print the parts. It is found that the apparent density of the rectangular block is the highest in all cases except at 100% saturation with 10-seconds delay. The apparent densities of the sphere and the cylinder are very close to each other. Also, the shrinkage percentage for the sphere is the highest then cylinder comes next, and the rectangular block comes last in all cases except when the core saturation is 100% and delay is 0 second where the cylinder shrinkage is higher than that of the sphere. The reason behind this is maybe the difference in the surface area of each part printed. It is noticed also that the relative density obtained is in the range of about 79% to about 85% and the shrinkage percentage is in the range of 36% to 55%.
{"title":"The Impact of the Printed Part Geometry on the Shrinkage and Relative Density in Binder Jetting Additive Manufacturing of Ceramics Powder","authors":"Suleiman Obeidat, Junkun Ma, Sophie Himelstein, Aniruddha Acharya","doi":"10.1115/imece2022-96385","DOIUrl":"https://doi.org/10.1115/imece2022-96385","url":null,"abstract":"\u0000 Additive manufacturing has been used extensively for the last decade in making different parts of different complexities. One of the additive manufacturing methods discussed in this work is binder jetting additive manufacturing (BJAM) process where a liquid-based binder is deposited on the powder bed to make the part layer by layer. In this work, ceramics particles are used to investigate the effect of the part geometry on the density and shrinkage of the part made. Three different shapes (spheres, cylinders, and rectangular blocks) of the same size are printed at 100%, 75% core saturation limit at zero second and 10-seconds delay using a binder jetting 3D printer at 0.2 mm layer thickness. The green parts are de-powdered and dried for 6–8 hours using a drying heater at 35° C then de-bound and sintered to improve the strength and the density of the part made. We use ceramics powder of particle size range 50–200 μm to print the parts. It is found that the apparent density of the rectangular block is the highest in all cases except at 100% saturation with 10-seconds delay. The apparent densities of the sphere and the cylinder are very close to each other. Also, the shrinkage percentage for the sphere is the highest then cylinder comes next, and the rectangular block comes last in all cases except when the core saturation is 100% and delay is 0 second where the cylinder shrinkage is higher than that of the sphere. The reason behind this is maybe the difference in the surface area of each part printed. It is noticed also that the relative density obtained is in the range of about 79% to about 85% and the shrinkage percentage is in the range of 36% to 55%.","PeriodicalId":141381,"journal":{"name":"Volume 2A: Advanced Manufacturing","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117305988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The overarching goal of this research work is to fabricate mechanically robust, dimensionally accurate, and porous dental structures, potentially used for the treatment of dental fractures, anomalies, as well as structural deformities with a focus on oral and maxillofacial surgery applications. In pursuit of this goal, the objective of the work is to investigate the mechanical properties of dental constructs, composed of medical-grade photopolymer resins and fabricated using digital light processing (DLP) process. The fabricated dental constructs not only are porous, but also have complex microstructures imparted by triply periodic minimal surface (TPMS) designs. This study tests the following central hypothesis: the mechanical properties of DLP-fabricated dental structures are significantly affected by photopolymer resin composition. In addition, the following research question is answered in this study: which of the chosen medical-grade photopolymer resins has the most significant impact on the mechanical properties of fabricated dental structures. DLP is a vat-photopolymerization additive manufacturing process, which has emerged as a high-resolution, robust method for the fabrication of a broad range of biological tissues and constructs for oral and dental tissue engineering applications. In the DLP process, the printing process takes place on the basis of radiation-curable resins or liquid photopolymers. Upon exposure to UV light, the resin materials become a solid (via chemical transformation) through a process known as photopolymerization. The DLP process consists of several parameters (such as layer thickness, cure depth, and UV lamp intensity) that significantly influence the functional properties of fabricated dental structures. In spite of the advantages and engendered applications, DLP is inherently complex; the complexity of the DLP process, to a great extent, stems from complex physio-chemical phenomena (such as UV light photopolymerization) in addition to resin (photopolymer)-process interactions, which may adversely affect not only the surface morphology, but also the mechanical properties and ultimately the functional characteristics of the fabricated dental scaffolds. As a result, integrated physics-guided process and material characterization would be required for optimal fabrication of porous and complex dental structures. Particularly in this study, the influence of three medical-grade photopolymer resins on the compression properties as well as the dimensional accuracy of TPMS dental constructs is systematically investigated. The compression properties of the DLP-fabricated dental constructs are measured using a compression testing machine. Furthermore, the dimensional accuracy of the dental constructs is measured via physical measurements and with the aid of a laser scanner. Besides, analysis of variance (ANOVA) is utilized to identify statistically significant photopolymer resin(s). The outcomes of this study pave the way
{"title":"Investigation of the Effects of Photopolymer Resin Composition on the Mechanical Properties of Complex Dental Constructs, Fabricated Using Digital Light Processing","authors":"Regan Raines, Roozbeh Salary","doi":"10.1115/imece2022-95049","DOIUrl":"https://doi.org/10.1115/imece2022-95049","url":null,"abstract":"\u0000 The overarching goal of this research work is to fabricate mechanically robust, dimensionally accurate, and porous dental structures, potentially used for the treatment of dental fractures, anomalies, as well as structural deformities with a focus on oral and maxillofacial surgery applications. In pursuit of this goal, the objective of the work is to investigate the mechanical properties of dental constructs, composed of medical-grade photopolymer resins and fabricated using digital light processing (DLP) process. The fabricated dental constructs not only are porous, but also have complex microstructures imparted by triply periodic minimal surface (TPMS) designs. This study tests the following central hypothesis: the mechanical properties of DLP-fabricated dental structures are significantly affected by photopolymer resin composition. In addition, the following research question is answered in this study: which of the chosen medical-grade photopolymer resins has the most significant impact on the mechanical properties of fabricated dental structures. DLP is a vat-photopolymerization additive manufacturing process, which has emerged as a high-resolution, robust method for the fabrication of a broad range of biological tissues and constructs for oral and dental tissue engineering applications. In the DLP process, the printing process takes place on the basis of radiation-curable resins or liquid photopolymers. Upon exposure to UV light, the resin materials become a solid (via chemical transformation) through a process known as photopolymerization. The DLP process consists of several parameters (such as layer thickness, cure depth, and UV lamp intensity) that significantly influence the functional properties of fabricated dental structures. In spite of the advantages and engendered applications, DLP is inherently complex; the complexity of the DLP process, to a great extent, stems from complex physio-chemical phenomena (such as UV light photopolymerization) in addition to resin (photopolymer)-process interactions, which may adversely affect not only the surface morphology, but also the mechanical properties and ultimately the functional characteristics of the fabricated dental scaffolds. As a result, integrated physics-guided process and material characterization would be required for optimal fabrication of porous and complex dental structures. Particularly in this study, the influence of three medical-grade photopolymer resins on the compression properties as well as the dimensional accuracy of TPMS dental constructs is systematically investigated. The compression properties of the DLP-fabricated dental constructs are measured using a compression testing machine. Furthermore, the dimensional accuracy of the dental constructs is measured via physical measurements and with the aid of a laser scanner. Besides, analysis of variance (ANOVA) is utilized to identify statistically significant photopolymer resin(s). The outcomes of this study pave the way","PeriodicalId":141381,"journal":{"name":"Volume 2A: Advanced Manufacturing","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116171508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Can Yang, Yunxiang Fu, Xiao-Hua Liu, Xiao-Hong Yin, Kewei Liu, Chun-Bo Li, Xiuhong Zheng, Bao-Hua Yang
Titanium alloys have been widely employed as essential raw materials for manufacturing implants in orthopedics due to their excellent biocompatibility, corrosion resistance, and mechanical properties similar to human bones. In order to form effective bonding between the titanium alloy implant and the human bone at an appropriate time, micro-structures are required to create on titanium alloy surfaces through surface modification, so that the bone cells can propagate and grow. Laser-induced micro/nano hierarchical structures on titanium alloy implants are capable of improving the adhesion, arrangement and proliferation of osteoblasts. However, significant micro-crack appears on the metal surfaces after the nanosecond laser treatment, which will do harm to mechanical and corrosion resistance performances of the implants and may even in turn damage patients’ health. This work aims at investigating the formation mechanism and influencing factors of micro-cracks to achieve laser-structured titanium alloy implants with reduced or even no micro-crack for orthopedic applications. Laser ablation experiments were conducted on titanium alloy surfaces to produce micro-grooves/protrusions. Specifically, three key laser process parameters such as the laser scanning speed (v), laser frequency (f), and scan repetition (n) were considered in terms of their influences on the crack morphology. The smaller the laser scanning speed, the large the micro-crack number and the more chaotic of their distribution. The speed of nanosecond laser processing should be increased to reduce the generation of micro-cracks. It can be inferred that micro-cracks on laser-structured titanium alloy surfaces are mainly ascribe to the generated thermal stress during laser processing.
{"title":"Micro-Crack Formation in Laser Structuring of Titanium Alloys for Orthopedic Applications","authors":"Can Yang, Yunxiang Fu, Xiao-Hua Liu, Xiao-Hong Yin, Kewei Liu, Chun-Bo Li, Xiuhong Zheng, Bao-Hua Yang","doi":"10.1115/imece2022-88668","DOIUrl":"https://doi.org/10.1115/imece2022-88668","url":null,"abstract":"\u0000 Titanium alloys have been widely employed as essential raw materials for manufacturing implants in orthopedics due to their excellent biocompatibility, corrosion resistance, and mechanical properties similar to human bones. In order to form effective bonding between the titanium alloy implant and the human bone at an appropriate time, micro-structures are required to create on titanium alloy surfaces through surface modification, so that the bone cells can propagate and grow. Laser-induced micro/nano hierarchical structures on titanium alloy implants are capable of improving the adhesion, arrangement and proliferation of osteoblasts. However, significant micro-crack appears on the metal surfaces after the nanosecond laser treatment, which will do harm to mechanical and corrosion resistance performances of the implants and may even in turn damage patients’ health. This work aims at investigating the formation mechanism and influencing factors of micro-cracks to achieve laser-structured titanium alloy implants with reduced or even no micro-crack for orthopedic applications. Laser ablation experiments were conducted on titanium alloy surfaces to produce micro-grooves/protrusions. Specifically, three key laser process parameters such as the laser scanning speed (v), laser frequency (f), and scan repetition (n) were considered in terms of their influences on the crack morphology. The smaller the laser scanning speed, the large the micro-crack number and the more chaotic of their distribution. The speed of nanosecond laser processing should be increased to reduce the generation of micro-cracks. It can be inferred that micro-cracks on laser-structured titanium alloy surfaces are mainly ascribe to the generated thermal stress during laser processing.","PeriodicalId":141381,"journal":{"name":"Volume 2A: Advanced Manufacturing","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126118575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. Robusto, S. Nassar, Joon Ha Lee, Marco Gerini-Romagnoli, M. De Agostinis
This study investigates the effect of shot-peened additively manufactured aluminum parts on the torque-tension relationship of threaded joints, as compared to extruded components. Steel flange head bolts are utilized. A computer-controlled RS torque-tension system is used for tightening test joints to a target preload, and frictional data is collected at a high sampling rate. A final group of additive manufactured specimens is analyzed to evaluate the effect of machining on the tribological response of the bolted joint. The underhead friction coefficient is measured over 5 consecutive tightenings, with and without disassembly and cooldown. The bearing surface topology is analyzed using an optical profilometer after each tightening. Fasteners and parts are ultrasonically cleaned, and tests are performed with no lubrication. Cooldown between consecutive tightenings had a significant effect on the frictional characteristics of non-machined additively manufactured joints. The lower surface integrity of the 3D printed components resulted in severe damage to the bearing surface after 5 tightening operations. Discussion of the results and conclusions are provided.
{"title":"Effect of Using 3D Printed Parts on the Torque-Tension Relationship of Threaded Joints","authors":"F. Robusto, S. Nassar, Joon Ha Lee, Marco Gerini-Romagnoli, M. De Agostinis","doi":"10.1115/imece2022-95614","DOIUrl":"https://doi.org/10.1115/imece2022-95614","url":null,"abstract":"\u0000 This study investigates the effect of shot-peened additively manufactured aluminum parts on the torque-tension relationship of threaded joints, as compared to extruded components. Steel flange head bolts are utilized. A computer-controlled RS torque-tension system is used for tightening test joints to a target preload, and frictional data is collected at a high sampling rate. A final group of additive manufactured specimens is analyzed to evaluate the effect of machining on the tribological response of the bolted joint. The underhead friction coefficient is measured over 5 consecutive tightenings, with and without disassembly and cooldown. The bearing surface topology is analyzed using an optical profilometer after each tightening. Fasteners and parts are ultrasonically cleaned, and tests are performed with no lubrication. Cooldown between consecutive tightenings had a significant effect on the frictional characteristics of non-machined additively manufactured joints. The lower surface integrity of the 3D printed components resulted in severe damage to the bearing surface after 5 tightening operations. Discussion of the results and conclusions are provided.","PeriodicalId":141381,"journal":{"name":"Volume 2A: Advanced Manufacturing","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127814219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The effect of cyclic corrosion on the static strength performance and reversibility performance of multi-material single lap joints is investigated. Aluminum substrates are adhesively bonded to Carbon-Fiber-Reinforced thermoplastic composite substrates using a commercially available two-part epoxy. The adhesive is modified with Thermally Expandable Particles at various concentrations by weight, with the purpose of allowing for joint separation using a charged RF coil to evaluate reversibility performance. The quasi-static performance of baseline joints is assessed, and the results from the various particle concentrations are compared. The cyclic corrosion testing of the Single Lap Joints is performed in accordance with a GMW 14872 3 stage laboratory standard for different lengths of duration up to 57 cycles. Quasi-static lap shear tests are performed at various stages of corrosion cycling and compared. Results and conclusions are provided.
{"title":"Effect of Salt Spray Cyclic Corrosion on the Mechanical and Reversibility Performance of Mixed Material Joints With Modified Adhesive","authors":"M. Burczyk, S. Nassar","doi":"10.1115/imece2022-94447","DOIUrl":"https://doi.org/10.1115/imece2022-94447","url":null,"abstract":"\u0000 The effect of cyclic corrosion on the static strength performance and reversibility performance of multi-material single lap joints is investigated. Aluminum substrates are adhesively bonded to Carbon-Fiber-Reinforced thermoplastic composite substrates using a commercially available two-part epoxy. The adhesive is modified with Thermally Expandable Particles at various concentrations by weight, with the purpose of allowing for joint separation using a charged RF coil to evaluate reversibility performance. The quasi-static performance of baseline joints is assessed, and the results from the various particle concentrations are compared. The cyclic corrosion testing of the Single Lap Joints is performed in accordance with a GMW 14872 3 stage laboratory standard for different lengths of duration up to 57 cycles. Quasi-static lap shear tests are performed at various stages of corrosion cycling and compared. Results and conclusions are provided.","PeriodicalId":141381,"journal":{"name":"Volume 2A: Advanced Manufacturing","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115993984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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