Author: Santosh Reddy Sama
Publisher:
ISBN:
Category :
Languages : en
Pages :
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Book Description
In recent years, Additive Manufacturing (AM) technologies are fueling a paradigm shift in the advanced manufacturing landscape across all industrial sectors. The metal casting industry is also taking advantage of the wide variety of rapid manufacturing solutions offered by AM processes. The metal casting industry supports about 90% of total manufactured goods and is expected to reach a market size of about 40 billion USD by 2025. Sand casting is the most widely used metal casting process and utilizes expendable molds that demand expensive tooling, high lead time and limited flexibility in their fabrication. In addition, limitations in process control and feasible gating and feeding systems, traditional sand casting experiences higher scrap rates. AM offers an alternative mold fabrication technology known as 3D Sand-Printing (3DSP) process that enables direct digital manufacturing of complex expendable sand molds and cores without any tooling requirements. Ever-growing interest in this indirect metal AM process is attributed to its ability to rapidly produce cores and molds for complex metal castings that are otherwise impossible to manufacture using conventional techniques. Knowledge-based design rules for this process are currently very limited and are progressively realized in an ad-hoc basis to produce economic low-volume castings. Despite the wealth of knowledge in metal AM, no work to date has been reported to take advantage of design complexity offered by 3DSP in developing optimal gating and feeding designs to mitigate casting defects. This thesis provides the first known investigation into the application of design freedom offered by 3DSP to transform and monitor sand casting performance. Non-conventional design rules for gating and risering (also known as rigging) systems are developed to reduce surface turbulence, oxide films, air entrapment, bubble damage and several other casting defects, and improved metallic yield. Several case studies are presented to illustrate the improved casting performance through systematically reengineering elements of the rigging system viz. pouring basin, sprue, runners and risers. Their efficacy is validated through computational simulations and experimental procedures. Of the various components of gating system, innovative sprue design provides the highest opportunity to improve casting quality. Numerical models for novel parabolic and conical-helix sprue profiles can be developed through constrained optimization algorithm based on principles of casting hydrodynamics to reduce surface turbulence. Computational flow simulations, computed tomography scanning, microstructure and mechanical characterization experiments are performed to validate that incorporation of 3D Sand-Printing featured mathematically optimized gating systems (particularly conical-helix sprues) to significantly improve the performance of sand castings.Finally, existing foundry technologies have very limited capabilities to monitor real-time flow conditions of liquid metal during mold filling. Two approaches for novel non-intrusive real-time mold fill monitoring by embedding inexpensive miniature Internet of Things (IoT) sensors into 3d sand-printed molds are proposed. These sensor technologies are based on the electrical properties of molten metals, the former measuring the magnetic flux generated by the conductive liquid and the latter measuring the interference of electric fields by modifying dielectric near the sensor. Experiments are conducted to evaluate the efficacy of both these concepts. Results from experiments validate that IoT sensors can be embedded into 3DSP molds to successfully monitor flow fields that can be used to benchmark simulation results and optimize gating systems.
Author: Ram A. Gullapalli
Publisher:
ISBN:
Category : Metal castings
Languages : en
Pages : 156
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Book Description
Sand casting has long been known to be an effective manufacturing method for metal casting and especially for parts of large dimensions and low production volume. But, for increasing complexity, the conventional sand casting process does have its limitations; one of them mainly being the high cost of tooling to create molds and cores. With the advent of additive manufacturing (AM), these limitations can be overcome by the use of a 3D sand printer which offers the unique advantage of geometric freedom. Previous research shows the cost benefits of 3D sand printing molds and cores when compared to traditional mold and core making methods. The line of research presented in this thesis introduces the idea of additive manufacturing at different stages of the sand casting process and investigates the decision-making process as well as the cost-based effects. This will enable foundries and manufacturers to integrate the use of AM machines more smoothly into their production process without the need for completely re-engineering the existing production system. A critical part of this thesis is the tooling cost estimation using a casting cost model that is significantly accurate to industry standard quotes. Based on these considerations, this thesis outlines three approaches for achieving this goal apart from traditional mold and core making methods. The first approach integrates 3D Printing at the pattern making level where the patterns and core-boxes are "printed" on an FDM printer. This eliminates the tooling costs associated with a traditional sand casting method. The second approach integrates 3D Printing at the core-making level by "mixing" traditional mold-making process and 3D sand printing process for core-making. The third approach, the 3D sand printer is used to create both the molds and the cores, thereby eliminating the need for traditional methods. An initial hypothesis is created which states that, for a given production volume, with increased complexity of the casting, additively manufacturing only the cores and conventionally manufacturing the molds is cost-feasible when compared to traditional manufacturing or 3D sand printing. It is finally concluded that the initial hypothesis is valid when part geometries are highly complex and production volumes range between medium to high. It is also concluded that a decision making tool based on the methodology provided can help determine a specific mixed manufacturing method for the manufacturer.
Author: Ryan Stebbins
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
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Book Description
Casting is one of the oldest manufacturing methods, dating to 5000 B.C. Its influence can still be seen today, accounting for a $110 billion impact on the US economy in 2019. Sand casting, is the most popular casting process due to its ability to produce relatively complex parts with almost any alloy at comparatively low costs, as well as manufacture both large components and small precision castings. Despite its prominence, casting has design limitations such as required draft angles and parting lines due to required tooling and patterns, which has led to the exploration of new manufacturing methods, such as additive manufacturing (AM). AM allows for increased part complexity, reduced material usage, part consolidation, usage of lattices, and decreased lead time between design and production. The rise of this novel technology is reflected in the large influx in publications and patents involving AM within in the past couple decades. However, its limitations in part size, cost, and available alloys prevent it from fully replacing casting. The merger of both sand casting and AM binder jetting into a hybrid manufacturing method is called 3D sand printing (3DSP), and it offers the benefits of both methods. With the advent of 3DSP, more complex geometries and castings are possible, allowing for the redesign and optimization of gating and rigging systems for defect reduction and improvements in casting quality. Despite research having already explored redesigning gating components like pouring basins, sprues, and runners using more complex mold geometries realizable through 3DSP, no research has considered the use of 3DSP for runner extensions. This thesis investigates various runner extension designs for the purpose of defect reduction. Out of the six different runner extension designs, three required 3DSP due to complexity. All designs were evaluated using simulation and experimental validation to ascertain their impact on casting quality. Designs were derived from literature review of gating system concepts. Simulations were completed using Flow-3D Cast v5 CFD software, comparing the resulting entrained air, tracer particles, and void particles present in the casting cavity. Results indicated difference between designs but required additional experimental comparisons to conclude runner extension impact. Designs were tested on manually poured Al319 cast plates, using a hybrid mold making method of both green sand and 3DSP extension molds. A total of eighteen plates were cast, three per design, all of which were scanned with computed tomography (CT) to determine the defect volume fraction present in the final castings. Three-point bending bars were machined from cast plates and tested to compare extension designs impact on mechanical properties. Statistical analysis of both mechanical performance and defect volume fraction showed no differences between runner extension designs. The results obtained in this thesis aid for the further optimization of gating systems and helping foundries reach zero defect casting.
Author: Jing Zhang
Publisher: Butterworth-Heinemann
ISBN: 0128123273
Category : Technology & Engineering
Languages : en
Pages : 364
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Book Description
Additive Manufacturing: Materials, Processes, Quantifications and Applications is designed to explain the engineering aspects and physical principles of available AM technologies and their most relevant applications. It begins with a review of the recent developments in this technology and then progresses to a discussion of the criteria needed to successfully select an AM technology for the embodiment of a particular design, discussing material compatibility, interfaces issues and strength requirements. The book concludes with a review of the applications in various industries, including bio, energy, aerospace and electronics. This book will be a must read for those interested in a practical, comprehensive introduction to additive manufacturing, an area with tremendous potential for producing high-value, complex, individually customized parts. As 3D printing technology advances, both in hardware and software, together with reduced materials cost and complexity of creating 3D printed items, these applications are quickly expanding into the mass market. Includes a discussion of the historical development and physical principles of current AM technologies Exposes readers to the engineering principles for evaluating and quantifying AM technologies Explores the uses of Additive Manufacturing in various industries, most notably aerospace, medical, energy and electronics
Author: Eyad S. Almaghariz
Publisher:
ISBN:
Category : Manufacturing processes
Languages : en
Pages : 140
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Book Description
The additive manufacturing industry has the potential to transform nearly every sector of our lives and jumpstart the next Industrial Revolution. Engineers and designers have been using 3D printers for more than three decades but mostly to make prototypes quickly and cheaply before they embark on the expensive business of tooling up a factory to produce the real things. In sand casting industries, a growing number of companies have adopted 3D sand printing to produce final casts. Yet recent research suggests that the use of 3D sand printing has barely begun to achieve its potential market. It is not surprising that executives are having difficulty adopting additive manufacturing; the technology has many second - order effects on business operations and economics. One of the most important factors is the lack of awareness of additive manufacturing's applications and values in the sand casting manufacturing process. The lack of awareness is significantly slowing down the adoption rates. This research will help executives to optimize their adoption decision by answering the question of "At what level of part complexity should sand printing be used instead of the conventional process in molds and cores manufacturing?" Moreover, this thesis defines and analyzes the geometric attributes which influence the parts' complexity. As known in the conventional sand casting process, the high level of complexity leads to higher manufacturing cost. On the other hand, in the additive manufacturing process, the manufacturing cost is fairly constant regardless of the level of complexity. Therefore, 3D sand printing provides a unique advantage that the increasing in geometric complexity of the part has no impact on the molds and cores manufacturing cost or what is known as "complexity for free."
Author: Md Moinuddin Shuvo
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
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Book Description
For the past few decades, additive manufacturing (AM) has revolutionized manufacturing industries with seven different process categories. While offering features that subtractive manufacturing lacks, AM has also facilitated the sand casting industry through the binder jetting process. 3D sand printing (3DSP) is a type of binder jetting that fabricates complex sand molds and cores layer upon layer without requiring pattern plates, core boxes, and flasks. While the traditional mold-making techniques lacked design freedom due to draft, parting lines, and pattern issues, 3DSP is free from these obligations and capable of making sand molds with complex shapes and intricate features incorporated within the mold. Based on the ad-hoc, knowledge-based, and steel alloy-dominated design rules, improper gating and feeding system design have always contributed to various casting defects and generated high scrap rates. Available gating and feeding system design features are structured upon the traditional mold-making process and do not consider the complex design freedom 3DSP offers. This dissertation is focused on studying different novel riser (feeder) shapes, riser neck, and vortex chambers (slag traps) in comparison with the benchmark design used in the industry in order to reduce shrinkage and slag/surface defects and utilize the design flexibility of 3DSP. Three different alloys- nickel aluminum bronze (NAB), low carbon steel (WCB/ASTM A216), and Aluminum alloy (A319), were studied, which accounted for different freezing ranges. Solidification modeling and experimental validations show up to 45% yield improvement. The results are discussed in terms of computational flow and solidification simulations. Experimental validation of the computational results includes statistical analysis, Ultrasonic testing (UT), computed tomography scanning (X-ray CT), and mechanical characterization of the cast parts. To the best of the author's knowledge, this is the first effort to develop a computational solidification and experimental validation-based framework to claim the design freedom provided by 3DSP in terms of casting's feeding mechanism.
Author: T V Ramana Rao
Publisher: New Age International
ISBN: 9788122408430
Category : Founding
Languages : en
Pages : 316
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Book Description
In This Book, The Topics/Syllabus Adequately Cover Metal Casting Subject In The Courses Of Mechanical, Production And Metallurgy Branches For B.E., B.Tech. As Well As Production And Industrial Metallurgy For M.Tech.With His Direct Experience In Metal Casting Industry And Teaching Academics The Author Attempts To Bridge The Gap Existing Between Essential Theory In Books And Vital Practical Applications In Industry.It Contains All The Molding Processes Normally Used With Details Of Ingredient Testing,Different Stages Of Casting Production Essential Theory Of Gating And Risering, As Well Asfinishing, Inspection And Quality Control.Over 80 Line Sketches Facilitate Easy Understanding. Information Given Through Over 20 Tables Help Easy Comprehension, Comparison And Remembrance. Exhaustive Examples Of Specific Components Normally Made By Casting Process Help To Build Confidence When Entering Industry. Over 200 Technical Books And Research Papers Upto May 1996 Are Referred. Examples Of Working Computer Programs Given, Form The Basis For Modern Practice-Oriented Projects In Final Year.For Practising Engineers, Managers And Entrepreneurs, This Book Provides Useful Theory And Practical Aspects On Foundry Management. Exhaustive Treatment Of Critical Gating & Risering With Many Industry Examples, Practical Solutions To Melting Problems, Casting Defects Analysis Through Cause-Effect Diagrams Will Be Very Useful. Essential Information. On Energy Conservation And Environmental Pollution Control Is Also Given In The Last Chapter.
Author:
Publisher: ASM International
ISBN: 1615031324
Category : Science
Languages : en
Pages : 271
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Book Description
Author: Nick Brooks
Publisher: Crowood
ISBN: 1847977308
Category : Crafts & Hobbies
Languages : en
Pages : 418
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Book Description
Mouldmaking and Casting is a technical manual of the many techniques of this ancient craft and art form. With step-by-step illustrations, it explains the materials required and the processes involved to create reproductions of a range of pieces. The book covers traditional techniques as well as today's more advanced technical methods.
Author: Sarbjeet Kaushal
Publisher: CRC Press
ISBN: 1040131905
Category : Technology & Engineering
Languages : en
Pages : 189
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Book Description
In this modern technological era, conserving and making better use of resources like energy, water, and other essential resources have recently been one of the main concerns for the manufacturing industry. To successfully compete against the competition, industries are replacing outdated manufacturing techniques with cutting-edge ones that are sustainable in terms of cost, energy usage, better product quality, and environmental safety. Green manufacturing has become one of the key priorities for attaining this. Green Manufacturing and Materials Processing Methods: Characterizations, Applications, and Design offers a critical review of the past work done in green manufacturing and material processing technologies. It presents recent research and development that is going on currently with green manufacturing techniques and discusses characterizations, applications, and the design aspect of materials processed through green manufacturing technologies. With a focus on the sustainability aspect, this book showcases new breakthroughs and comparisons of cutting-edge sustainable manufacturing and materials processing with currently available conventional methods. Highlights throughout the book are on improvements used in various manufacturing processes such as casting, joining, drilling, surface engineering, sintering, and composite manufacturing. This book will serve as a first-hand information source for academic researchers and industrial firms. With the help of this book, readers will have a unique opportunity to comprehend and evaluate recent advancements in green manufacturing and material processing technology. This book will be the go-to resource for individuals who desire to do research or development in the area of sustainable manufacturing and material processing technologies.
