Casting Practices Influencing Inclusion Distribution in Al-Billets
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Machining Accuracy of Machine Tools
Technical Information Machining Accuracy of Machine Tools Productivity and accuracy of machine tools are important competition aspects. Rapidly changing operating conditions for machine tools, however, make it diffi cult to increase productivity and accuracy. In the manufacture of parts, increasingly small batch sizes have to be produced economically, and yet accurately. In the aerospace industry, maximum cutting capacity is needed for the roughing processes, whereas the subsequent fi nishing processes must be executed with maximum precision. For milling high-quality molds, high material removal rates are required during roughing and excellent surface quality must be obtained after fi nishing. At the same time, maximum contouring feed rates are necessary to realize the required minimum distances between the paths within acceptable machining times. Thermal accuracy of machine tools is becoming increasingly important considering the strongly varying operating conditions in manufacturing. Especially with small production batches that require constantly changing machining tasks, a thermally stable condition cannot be reached. At the same time, the accuracy of the fi rst workpiece is becoming very important for the profi tability of production orders. Constant changes between drilling, roughing and fi nishing operations contribute to the fl uctuations in the thermal condition of a machine tool. During the roughing operations, the milling rates increase to values above 80 %, whereas values below 10 % are reached during fi nishing operations. The increasingly high accelerations and feed rates cause heating of the recirculating ball screw in linear feed drives. Position measurement in the feed drives therefore plays a central role in stabilizing the thermal behavior of machine tools. -
Extrusion.Pdf
Extrusion: Second Edition Copyright © 2006 ASM International® M. Bauser, G. Sauer, K. Siegert, editors, p 195-321 All rights reserved. DOI:10.1361/exse2006p195 www.asminternational.org CHAPTER 5 The Production of Extruded Semifinished Products from Metallic Materials* THE HOT-WORKING PROCESS extrusion ered to be the most important of the hot-working is, in contrast to other compressive deformation processes. processes used to produce semifinished prod- ucts, a deformation process with pure compres- sive forces in all three force directions. These favorable deformation conditions do not exist in other production processes for semifinished products. Even in rolling, which is the most im- Extrusion of Materials with portant compressive working process for pro- ducing semifinished products, tensile forces oc- Working Temperatures cur in the acceleration zone of the roll gap as between 0 and 300 ЊC well as in the cross rolling process used to pierce blanks in the rolling of steel tubes. These Gu¨nther Sauer* tensile forces cause problems in the rolled prod- uct if the deformation conditions are not opti- mized. The benefits of this three-dimensional compression in terms of deformation technol- 5.1 Extrusion of Semifinished ogy, which have already been discussed in this Products in Tin Alloys book, can be clearly seen in Fig. 5.1 based on experimental results for face-centred cubic (fcc) Tin is a silver-white, very soft metal with a aluminum and zinc with its hexagonal lattice stable tetragonal lattice in the temperature range structure. 20 to 161 ЊC. The pure metal has a density of The extensive variations in the extrusion pro- 7.28 g/cm3 and a melting point of 232 ЊC. -
Corrosion of Refractories by Denis A
A Chapter in the Refractories Handbook, edited by Charles A. Schacht, and to be published by Marcel Dekker, Inc., New York, NY 10016 Corrosion of Refractories by Denis A. Brosnan, PhD, PE Clemson University Clemson, SC 29634-0971 Introduction Refractories are used at elevated temperatures for structural purposes and they are used in many cases to contain a high temperature corrosive environment. This corrosive environment usually contains liquid (melted) phases that participate in chemical reactions with the refractory at the elevated temperatures resulting in refractory consumption or wear. It is usually not immediately obvious, but the oxidation and reduction state of the environment (as “redox” conditions or oxygen “activity”) can participate in and influence the chemical reactions that take place. Along with chemical reactions during corrosion, physical changes occur that may be accelerated by the corrosion process. Corrosion of refractories can be defined for the purposes of this discussion as follows: Corrosion of Refractories – refractory wear by loss of thickness and mass from the exposed face of the refractory as a consequence of chemical attack by a corroding fluid in a process in which the refractory and the corroding fluid react approaching chemical equilibrium in the zone of contact between the refractory and the fluid. It is an essential point that corrosion reactions proceed in a direction toward localized chemical equilibrium. This means that phase equilibrium diagrams can be used to analyze corrosion situations and to predict chemical strategies to minimize corrosion and wear rates. This gives persons interested in refractory corrosion two options. The first is to view corrosion as a chemical and physical process without a detailed application of phase equilibrium diagrams – called the “phenomenological approach”. -
Untraditional Synthesis of Boron-Containing Superhard and Refractory Materials - a Review B
G.J. E.D.T., Vol. 2(1) 2013:21-26 ISSN 2319 – 7293 UNTRADITIONAL SYNTHESIS OF BORON-CONTAINING SUPERHARD AND REFRACTORY MATERIALS - A REVIEW B. Agyei-Tuffour1,2, E. Annan1,2, E. R. Rwenyagila1, E. Ampaw1, E. Arthur1, K. Mustapha1, S. Kolawole1, W. O. Soboyejo1,3, & D. D. Radev1,4 1Department of Materials Science and Engineering, African University of Science and Technology, Abuja-Nigeria 2Department of Materials Science and Engineering, Private Mail Bag, University of Ghana, Legon-Accra. 3Department of Mechanical and Aerospace Engineering, Princeton University, USA. 4Institute of General and Inorganic Chemistry, Bulgaria Academy of Sciences, Sofia-Bulgaria Abstract Boron-containing ceramics find large application in production of superhard and high-temperature materials with application in nuclear and aerospace techniques, military industry etc. The synthesis methods are decisive for the complexity of chemical, morphological and technological properties of these materials. The traditional high-temperature synthesis methods have some disadvantages leading to inconstancy of the product composition due to the boron evaporation, degradation of the furnace materials and contamination of the products, high energy losses etc. Here we show the advantages of some untraditional synthesis methods like direct mechanical synthesis and self propagating high-temperature synthesis (SHS) in the production of titanium diboride (TiB2), zirconium diboride (ZrB2) and production of dense boron carbide (B4C) based materials. Using SEM, TEM, XRD and analytical chemical methods, it was shown that diborides of titanium and zirconium have appropriate properties for production of dense ceramic materials. Using the method of mechanically-assisted sintering high-dense B4C-based ceramic materials was obtained. It was shown that the mechanical properties of materials obtained by pressureless sintering are close or overcome the corresponding properties of boron carbide densified by the method of hot pressing. -
Vibrations in Metal Cutting Measurement, Analysis and Reduction
Vibrations in Metal Cutting Measurement, Analysis and Reduction Linus Pettersson Ronneby, March 2002 Department of Telecommunications and Signal Processing Blekinge Institute of Technology 372 25 Ronneby, Sweden c Linus Pettersson Licentiate Dissertation Series No. 01/02 ISSN 1650-2140 ISBN 91-7295-008-0 Published 2002 Printed by Kaserntryckeriet AB Karlskrona 2002 Sweden v Abstract Vibration and noise in metal cutting are ubiquitous problems in the workshop. The turning operation is one kind of metal cutting that exhibits vibration related problems. Today the industry aims at smaller tolerances in surface finish. Harder regulations in terms of the noise levels in the operator environment are also central. One step towards a solution to the noise and vibration problems is to investigate what kind of vibrations that are present in a turning operation. The vibrations in a boring operation have been put under scrutiny in the first part of this thesis. Analytical models have been compared with experimental results and the vibration pattern has been determined. The second part of the thesis deals with active vibration control in external turning operations. By embedding a piezo-ceramic actuator and an accelerometer into a tool holder it was possible to obtain a solution that can be fitted in a standard lathe. The control system consists of the active tool holder, a control system based on the filtered-X LMS algorithm and an amplifier designed for capacitive loads. The vibration level using this technique can be reduced by as much as 40 dB during an external turning operation. vii Preface The work presented in this licentiate thesis has been performed at the department of Telecommunications and Signal Processing at Blekinge Institute of Technology. -
Introduction to Selecting Milling Tools Iimportant Decisions for the Selection of Cutting Tools for Standard Milling Operations
Introduction to Selecting Milling Tools IImportant decisions for the selection of cutting tools for standard milling operations The variety of shapes and materials machined on modern milling machines makes it impera- tive for machine operators to understand the decision-making process for selecting suitable cutting tools for each job. This course curriculum contains 16-hours of material for instructors to get their students ready to make basic decisions about which tools are suitable for standard milling operations. ©2016 MachiningCloud, Inc. All rights reserved. Table of Contents Introduction .................................................................................................................................... 2 Audience ..................................................................................................................................... 2 Purpose ....................................................................................................................................... 2 Lesson Objectives ........................................................................................................................ 2 Where to Start: A Blueprint and a Plan .......................................................................................... 3 Decision 1: What type of machining is needed? ............................................................................ 7 Decision 2: What is the workpiece material? ................................................................................. 7 ISO Material -
Ats 34 and 154 Cm Stainless Heat Treat Procedure
ATS 34 AND 154 CM STAINLESS HEAT TREAT PROCEDURE This is an oil hardening grade of steel which will require oil quenching. The oil should be a warm, thin quenching oil that contains a safe flash point. Olive oil has been used as a sub stitute. As a rule of thumb, there should be a gallon of oil for each pound of steel. For , warming the oil before quenching, you may heat a piece of steel and drop it in the oil. 1.) Wrap blades in stainless tool wrap and leave an extra two inches on each end of the package. (This will be for handling purposes going into the quench as described below.) We suggest a double wrap for this grade. The edges of the foil should be double crimped, being careful to avoid hav ing even a pin hole in the wrap. 2 . ) Place in the furnace and heat to 1900"F. After reaching this temperature, immediately start timing the soak time of 25-30 minutes. 3.) After the soak time has elapsed, very quickly and carefully pull the package out with tongs~ place over the quench tank and snip the end of the package allowing the blades to drop into the oil. You should have a wire basket in the quench tank for raising and lowering the blades rather than have them lie s till. Gases are released in the quench and would form a "trap" around the steel unless you keep them movi~g for a minute or so. *IMPORTANT--It is very important that the blades enter the oil quench as quickly as possible after leaving the furnace ! Full hardness would not be reached if this step is not followed. -
The White Book of STEEL
The white book of STEEL The white book of steel worldsteel represents approximately 170 steel producers (including 17 of the world’s 20 largest steel companies), national and regional steel industry associations and steel research institutes. worldsteel members represent around 85% of world steel production. worldsteel acts as the focal point for the steel industry, providing global leadership on all major strategic issues affecting the industry, particularly focusing on economic, environmental and social sustainability. worldsteel has taken all possible steps to check and confirm the facts contained in this book – however, some elements will inevitably be open to interpretation. worldsteel does not accept any liability for the accuracy of data, information, opinions or for any printing errors. The white book of steel © World Steel Association 2012 ISBN 978-2-930069-67-8 Design by double-id.com Copywriting by Pyramidion.be This publication is printed on MultiDesign paper. MultiDesign is certified by the Forestry Stewardship Council as environmentally-responsible paper. contEntS Steel before the 18th century 6 Amazing steel 18th to 19th centuries 12 Revolution! 20th century global expansion, 1900-1970s 20 Steel age End of 20th century, start of 21st 32 Going for growth: Innovation of scale Steel industry today & future developments 44 Sustainable steel Glossary 48 Website 50 Please refer to the glossary section on page 48 to find the definition of the words highlighted in blue throughout the book. Detail of India from Ptolemy’s world map. Iron was first found in meteorites (‘gift of the gods’) then thousands of years later was developed into steel, the discovery of which helped shape the ancient (and modern) world 6 Steel bEforE thE 18th cEntury Amazing steel Ever since our ancestors started to mine and smelt iron, they began producing steel. -
Metalworking & Forging Safety and Tool Use Certification (STUC
Metalworking & Forging Safety and Tool Use Certification (STUC) STUC-at-Home; Fall 2020 Thank you for registering for 1 or more Department STUCs! Fall 2020 OSA dates are September 14- December 23. We look forward to having you in the Shops soon! In this STUC packet, you will find: 1. CIADC Health Safety Guidelines (Before Entering and In-Shop) • Our guide on health safety measures that Staff, Students, Members, and Visitors must follow to ensure the health safety of everyone while at CIADC. We appreciate your cooperation with this! For more details about our Healthy Safety Plan, click here. 2. Metal Shop-Specific PPE – Shared vs. Purchase • What PPE is required in the Metal Shop, and what we require/recommend YOU purchase 3. Metalworking & Forging Department STUC • **NEW** Items in Department • General and Department-specific information for you to know 4. Metalworking & Forging Department Material & Supply Purchase Form • What is currently offered 4-Sale in the Metal Shop 5. Metalworking & Forging Department Resource List • Where else to purchase material, supplies, PPE, etc. specific to Department 6. **NEW** Members: CNC Machining Services 7. OSA Reservation Procedure • To ensure we do not exceed the maximum safe amount of people in Shops during OSA, we are implementing an OSA reservation system 8. Programming Schedule • Class and OSA schedule for the upcoming term To Complete STUC: 1. Submit shop-specific online STUC quiz (click here for link) 2. Pre-Pay for 5-OSAs (Access Members only; will be invoiced) 3. Renew Liability Waiver (as -
Mechanical Metalworking: from Manual to Computer-Based Processes
August 04, 2021 Mechanical metalworking: from manual to computer-based processes Just like in an ordinary kitchen, there is more to the steelmaker’s kitchen than just the processes where high temperature plays a crucial role, such as boiling, roasting or baking. Before a dish can be served, it needs additional work to make it more appealing. The same is true of metals. Prior to their use, plates, tubes, rods and complex steel castings are subject to cold forming by special metalworking machines and lathes, which become more and more sophisticated each year. History of mechanical metalworking Let’s look first into the history of mechanical metalworking and its origins. Unlike many other processes that are unique to steelmaking, some ideas related to the mechanical working of metal surfaces came from related areas. The ancient Egyptians had devices for drilling holes in stones. Wood machining equipment that later evolved into turning lathes existed in the sixth and seventh centuries BC. Yet these types of processes were not applied to metals for hundreds of years. For a long time, metal surface treatment had several restricting factors. First, it required harder tools. Second, small-batch production did not need high-precision metalworking. Third, the industrial revolution and mass production of uniform products only became a reality in the 18th-19th centuries. The third reason was a key prerequisite for the appearance of mechanical metalworking. Smiths that made goods for individual orders gave way to large industrial manufacturers and factories that had the capacity to produce large quantities of uniform metal goods. Gunsmiths were among the first to appreciate the importance of standardised metalworking. -
Fire Protection of Steel Structures: Examples of Applications
Fire protection of steel structures: examples of applications Autor(en): Brozzetti, Jacques / Pettersson, Ove / Law, Margaret Objekttyp: Article Zeitschrift: IABSE proceedings = Mémoires AIPC = IVBH Abhandlungen Band (Jahr): 7 (1983) Heft P-61: Fire protection of steel structures: examples of applications PDF erstellt am: 06.10.2021 Persistenter Link: http://doi.org/10.5169/seals-37489 Nutzungsbedingungen Die ETH-Bibliothek ist Anbieterin der digitalisierten Zeitschriften. Sie besitzt keine Urheberrechte an den Inhalten der Zeitschriften. Die Rechte liegen in der Regel bei den Herausgebern. Die auf der Plattform e-periodica veröffentlichten Dokumente stehen für nicht-kommerzielle Zwecke in Lehre und Forschung sowie für die private Nutzung frei zur Verfügung. Einzelne Dateien oder Ausdrucke aus diesem Angebot können zusammen mit diesen Nutzungsbedingungen und den korrekten Herkunftsbezeichnungen weitergegeben werden. Das Veröffentlichen von Bildern in Print- und Online-Publikationen ist nur mit vorheriger Genehmigung der Rechteinhaber erlaubt. Die systematische Speicherung von Teilen des elektronischen Angebots auf anderen Servern bedarf ebenfalls des schriftlichen Einverständnisses der Rechteinhaber. Haftungsausschluss Alle Angaben erfolgen ohne Gewähr für Vollständigkeit oder Richtigkeit. Es wird keine Haftung übernommen für Schäden durch die Verwendung von Informationen aus diesem Online-Angebot oder durch das Fehlen von Informationen. Dies gilt auch für Inhalte Dritter, die über dieses Angebot zugänglich sind. Ein Dienst der ETH-Bibliothek ETH Zürich, Rämistrasse 101, 8092 Zürich, Schweiz, www.library.ethz.ch http://www.e-periodica.ch J% IABSE periodica 2/1983 IABSE PROCEEDINGS P-61/83 69 Fire Protection of Steel Structures — Examples of Applications Protection contre le feu des structures acier — Quelques exemples d'applications Brandschutz der Stahlkonstruktionen — Einige Anwendungsbeispiele Jacques BROZZETTI Margaret LAW Dir., Dep. -
WELD 1030 Pattern Development
PELLISSIPPI STATE COMMUNITY COLLEGE MASTER SYLLABUS PATTERN DEVELOPMENT WELD 1030 Class Hours: 2.0 Credit Hours: 2 Laboratory Hours: 2.0 Revised: Spring 2017 Catalog Course Description With an emphasis on the practical applications of pattern development, students construct basic forms using parallel line pattern development techniques. The course also introduces students to tools of the trade, geometric construction and bend allowance computations. Prerequisites NONE Corequisites MATH 1010 or MATH 1530 or MATH 1630 or MATH 1710 or MATH 1720 or MATH 1730 or MATH 1830 or MATH 1910 Textbook(s) and Other Course Materials Sheet Metal, Latest Edition, Leo A. Meyer, American Technical Publishers, Week/Unit/Topic Basis Week Topic 1. Introduction, Sheet Metal Working Tools and Machinery 2. Fasteners for Sheet Metal, Using Patterns and Cutting Metal 3. Punching, Drilling, and Riveting Folding Edges and Making Seams 4. Turning, Barring and Raising, Forming, Crimping, Beading and Grooving 5. Soldering 6. Drawing for Pattern Drafting 7. Making and Notching Simple Patterns 8. Parallel Line Development 9. Lab Projects 10. Review / Final Exam Welding Technology General Outcomes (Educational objectives) 1. Reach their full potential in the welding field. 2. Use the correct procedure in setting up equipment, and the skills used in welding. 3. Use Shielded Metal Arc Welding, Gas Metal Arc Welding, and Gas Tungsten Arc Welding machines in both pipe and plate welding. 4. Explain the physical characteristics of different metals 5. Develop the cognitive and physical skills necessary to pass certification tests. 6. Apply welding knowledge to effectively utilize problem solving skills as it relates to the operation of equipment in the industry.