environmentally conscious design & manufacturing (me592) date: april 10, 2000 slide:1...
Post on 19-Dec-2015
225 views
TRANSCRIPT
Environmentally Conscious Design & Manufacturing (ME592)
Date: April 10, 2000 Slide:1
Environmentally Conscious Design & Manufacturing
Class 16: Material Selection
Prof. S. M. Pandit
Environmentally Conscious Design & Manufacturing (ME592)
Date: April 10, 2000 Slide:2
Agenda
• Generic automobile materials
• Engineering materials
• Properties of materials
• Guidelines for materials selection
• Steels, cast iron, alloys, and
ceramics
Environmentally Conscious Design & Manufacturing (ME592)
Date: April 10, 2000 Slide:3
Generic Automobile Materials
Environmentally Conscious Design & Manufacturing (ME592)
Date: April 10, 2000 Slide:4
The Flow of Aluminum
Unit: kg
Environmentally Conscious Design & Manufacturing (ME592)
Date: April 10, 2000 Slide:5
Materials Use in Automobile
Unit: kg
Environmentally Conscious Design & Manufacturing (ME592)
Date: April 10, 2000 Slide:6
Design Process
Product Function?Need for a device or product
Synthesis (Creativity-Ideas)
Material selection
Product part(prototype)
Put Partinto Service
Redesign
Change • material?• process?
UnsatisfactoryEvaluate
performance
Satisfactory
Environmentally Conscious Design & Manufacturing (ME592)
Date: April 10, 2000 Slide:7
Engineering Materials• Ferrous metals: carbon, alloy, stainless, and tool and
die steels
• Nonferrous metals and alloys: aluminum, magnesium, copper, nickel, titanium, low-melting alloys
• Plastics: thermoplastics, thermosets, and elastomers
• Ceramics: glass ceramics, glasses, graphite, and diamond
• Composite materials: reforced plastics, metal-matrix and ceramic-matrix composites, and honeycomb structures.
Environmentally Conscious Design & Manufacturing (ME592)
Date: April 10, 2000 Slide:8
Engineering Materials (cont.)
High modulusAbrasion resistant
MetalsPoor corrosion Resistance
Ceramicsbrittle
GlassesBrittle
Elastomerscreep at low temp
Polymerscreep at low temp Composites
Corrosion resistant Corrosion resistant
Low modulusHigh strength
High strength, Moderate modulus, High ductility
Environmentally Conscious Design & Manufacturing (ME592)
Date: April 10, 2000 Slide:9
Properties of Materials
• Mechanical properties:strength, toughness, ductility,hardness, elasticity, fatigue, and creep
• Physical properties: density, thermal expansion, conductivity, specific heat, melting point, and electrical and magnetic properties
• Chemical properties:oxidation, corrosion, toxicity,and flammability
• Manufacturing properties: castability, formability, machinability, weldability, and hardenability by heat treatment.
Environmentally Conscious Design & Manufacturing (ME592)
Date: April 10, 2000 Slide:10
Properties of Materials (cont.)
ProductionComposition Recycling
Energy Effluents
Resource depletion
Environmental Aspects
Environmentally Conscious Design & Manufacturing (ME592)
Date: April 10, 2000 Slide:11
Guidelines for Materials Selection
Traditional guidelines for materials selection:
• Desired mechanical, physical, and chemical properties
• Shapes of commercially available materials
• Reliability of supply
• Cost of materials and processing
Environmentally Conscious Design & Manufacturing (ME592)
Date: April 10, 2000 Slide:12
Guidelines for Materials Selection (Cont.)
Guidelines for materials selection from the ECDM viewpoint:
• Choose abundant, non-toxic, nonregulated materials
• Choose materials familiar to nature• Choose easily recycled materials• Minimize environmental impact without loss
of product quality
Environmentally Conscious Design & Manufacturing (ME592)
Date: April 10, 2000 Slide:13
Low-Impact Materials
Non-hazardous materials Non-exhaustable/renewable materials Low-energy content materials Recycled and recyclable materials
Environmentally Conscious Design & Manufacturing (ME592)
Date: April 10, 2000 Slide:14
Energy Aspects
• Energy to mine raw materials
• Energy to extract and refine ore
• Energy to from product
• Energy to ship product
• Energy to use product
• Energy to disposal of product
Environmentally Conscious Design & Manufacturing (ME592)
Date: April 10, 2000 Slide:15
Part is remanufacturable – Example: starter, transmission
Steel, aluminum, lead, and copper have good recycling records.
Organic material for energy recovery, that cannot be recycled. Example: Tires, rubber in hoses.
Inorganic material with no known technology for recycling.
Material Recyclability
Environmentally Conscious Design & Manufacturing (ME592)
Date: April 10, 2000 Slide:16
• Types of recycled material–home scrap–pre-consumer–post-consumer
• Design considerations–ease of disassembly–material identification–simplification and parts consolidation–material selection and compatibility
Material Life Extension
Environmentally Conscious Design & Manufacturing (ME592)
Date: April 10, 2000 Slide:17
Improvements of Existing Products
• Substitution (water based coatings instead of volatile organic compounds)
• Reformulation (e.g., unleaded gasoline is a reformulation of the leaded variety)
• Elimination
Environmentally Conscious Design & Manufacturing (ME592)
Date: April 10, 2000 Slide:18
Reduced Material Intensiveness
• Dematerialization- Less materials means less consumption, saves energy and money.
• Shared use of product
• Integration of functions
• Functional optimization of product and components
Environmentally Conscious Design & Manufacturing (ME592)
Date: April 10, 2000 Slide:19
• Weight reductions reduce energy needed to move the product.
• Avoid over-dimensioning the product via good design
• Reduction in volume (space required for transport and storage)
Reduction of Material Usage
Environmentally Conscious Design & Manufacturing (ME592)
Date: April 10, 2000 Slide:20
Example (Xerox)
Source: Calkin, P., 1998
Environmentally Conscious Design & Manufacturing (ME592)
Date: April 10, 2000 Slide:21
The Results of Efforts
• Reduced solid waste generation by 73 percent
• Increased the factory recycle rate by 141 percent
• Reduced releases to the environment by 94 percent
• Realized over $ 200 million in annual savings
Environmentally Conscious Design & Manufacturing (ME592)
Date: April 10, 2000 Slide:22
Steels
Plain carbon steels• Low-carbon steel (0.02% - 0.3%C), used for manufacturing
bolts and nuts, bars and rods• Medium-carbon steel (0.3% - 0.6 %C), used to harden tools
such as hammers, screw drivers, and wrenches.• High-carbon steel (0.6 % - 1.5%C), for edge cutting tools
such as punches, dies, taps, and reamers.
Alloy steels• Addition of alloying elements (Cr, Mn, Mo, Ni, T, V)
improves mechanical properties of steels
Environmentally Conscious Design & Manufacturing (ME592)
Date: April 10, 2000 Slide:23
Cast Iron
•Alloy of iron and carbon (1.7%-4.5%C)•Gray cast iron, used in machine tool, automotive, and other industries•White cast iron, used for the production of malleable iron casting•Chilled cast iron, used for products with wear-resisting surface•Alloy cast iron, used in automotive engine, brake, and other systems, machine tool casting, etc.•Malleable iron castings, used in industrial applications that require a highly machinable metal, great strength ductility and resistance to shock.
Environmentally Conscious Design & Manufacturing (ME592)
Date: April 10, 2000 Slide:24
Aluminum and its AlloyProperties:• High strength-to-weight ratio • Resistance to corrosion• High thermal and electrical conductivity• nontoxicity, ease of recycling• reflectivity, ease of machinability
Uses:• Con and foil• Construction (building etc.)• Transportation (aircraft, automobile, etc.) • Electrical conductors, and appliances
Environmentally Conscious Design & Manufacturing (ME592)
Date: April 10, 2000 Slide:25
Nonferrous Alloys
• Copper-based alloys (ex. Brasses and bronzes) - good strength, hardness, conductivity.
• Aluminum-based alloys
- increased tensile strength, weldability, ductility
• Nickel-based alloys- high strength and corrosion resistance
• Zinc-based alloys- good corrosion resistance, strength, and ductility
Environmentally Conscious Design & Manufacturing (ME592)
Date: April 10, 2000 Slide:26
Ceramics
• TypesOxide ceramics, carbides, nitrides, cermets, sialon
• General propertiesBrittle, high strength, high hardness, low toughness, low density, low thermal expansion, and low thermal and electrical conductivity
• ApplicationsAutomobile components, electronics, cutting tools, fiber optics