TVT 02/11 1

THE NEED FOR MATERIAL SELECTION Rapid Development in Material Technology: - Many new materials - Increased use of advanced materials - New manufacturing methods - Entirely new design configurations feasible - Properties of existing materials improved - Increased competition between materials

TVT 02/11 2

INTUITIVE METHODS IN MATERIAL SELECTION

1. First best material The material is selected among the few materials the design engineer is familiar with

2. Same material as for a similar part 3. Problem solving material selection

A property has given rise to problems. A new material is chosen in the same group of material with a higher value of the property.

4. Searching material selection The designer takes more or less randomly into account one requirement at the time.

Drawbacks with Intuitive Methods: - Important requirements have often given rise to failures in operation. - First solution at hand is taken which is not very likely to be good solution. - Unconventional solutions are not considered e.g. advanced materials are not analysed. - The solution is typically far from the optimum giving the part poor competitiveness.

TVT 02/11 3

SYSTEMATIC MATERIAL SELECTION

Why? - To make full use of the engineereing materials. - To avoid unnecessarily expensive structures. - To avoid failures. When? - A new product is developed. - A product is modified and redesigned. - Failures have occured. Who? - Design engineers in collaboration with materials engineers. How ? - Specify the requirements for the component. - Transfer the requirements to materials properties. - Find the material groups that satisfy the specification. - Find the individual materials that satisfy the specification. - Identify the "best" materials that satisfy the specification.

TVT 02/11 4

CASE STUDY: THE EVOLUTION OF MATERIALS IN VACUUM CLEANERS

(a) the hand-powered bellows cleaner of 1900, largely made of wood and leather (b) the cylinder cleaner of 1950 (c) the lightweight cleaner of 1985, almost entirely made of polymer (d) a centrifugal dust-extraction cleaner of 1997

TVT 02/11 5

DESIGN – INTRODUCTION Mechanical design deals with the physical principles, the proper functioning and the production of mechanical systems ( Industrial design is the professional service of creating and developing concepts and specifications that optimize the function, value and appearance of products and systems for the mutual benefit of both user and manufacturer (Industrial Designers Society of America) Types of design: Original design: involves a new idea or working principle (the ball-point pen, the compact disc). Need new materials: high-purity silicon enabled the transistor; high-purity glass, the optical fiber; high coercive-force magnets. Adaptive or developmental design: takes an existing concept and seeks an incremental advance in performance through a refinement of the working principle. polymers replacing metals in household appliances; carbon fiber replacing wood in sports goods. Variant design: involves a change of scale or dimension or detailing without change of function or the method of achieving it: the scaling up of boilers, turbines…

TVT 02/11 6

DESIGN PROCESS

TVT 02/11 7

APPROACH TECHNICAL SYSTEM The analysis of a technical system as a breakdown into assemblies and components. Material and process selection is at the component level.

This approach helps thinking about alternative designs.

TVT 02/11 8

DESIGN TOOLS AND MATERIALS DATA DFM:Design for Manufacture DFA: Design for Assembly

TVT 02/11 9

FUNCTION, MATERIAL, SHAPE, AND PROCESS

Design problem involving materials investigation and design of materials

- Select the right material from the many thousands that are available. - Select the right process and manufacture. - Deterioration of material properties that may occur during service operation - Consideration is that of economics: What will the finished product cost?

TVT 02/11 10

CASE STUDY: DEVICES TO OPEN CORKED BOTTLES The market need: a device is sought to allow access to wine contained in a corked bottle.

TVT 02/11 11

TVT 02/11 12

SOME CORK REMOVERS

TVT 02/11 13

THE FAMILIES OF ENGINEERING MATERIALS

Advanced material: those used in high-technology applications: semiconductors, biomaterials, smart materials, and nanoengineered materials.

TVT 02/11 14

METALS Metals: composed of one or more metallic elements (such as iron, aluminum, copper, titanium, gold, and nickel), and often also nonmetallic elements (for example, carbon, nitrogen, and oxygen) in relatively small amounts.

TVT 02/11 15

CERAMICS Ceramics: are compounds between metallic and nonmetallic elements; they are most frequently oxides, nitrides, and carbides.

TVT 02/11 16

POLYMERS Polymers: are organic compounds that are chemically based on carbon, hydrogen, and other nonmetallic elements (viz.O,N, and Si) and they have very large molecular structures, often chain-like in nature that have a backbone of carbon atoms.

TVT 02/11 17

COMPOSITES Composite is composed of two (or more) individual materials, which come from the categories discussed above—viz., metals, ceramics, and polyme. The design goal of a composite is to achieve a combination of properties that is not displayed by any single material, and also to incorporate the best characteristics of each of the component materials.

TVT 02/11 18

PROPERTY-PROFILE

TVT 02/11 19

TVT 02/11 20

TVT 02/11 21

MECHANICAL PROPERTIES

TVT 02/11 22

OTHERS PROPERTIES