CH8. Ch15

Over 50% of all metallic zinc is used for galvanizing Steel or iron may be hot dipped or be coated using electrolytic plating Provides excellent corrosion resistance Also used as the base metal in many die casting alloys these are related to ______-based alloys

Zinc-Based Alloys

Made by mixing ceramic particles with molten aluminum and blowing gas into the mixture Resembles metallic Styrofoam Provide excellent energy absorption, thermal insulation, vibration damping, and sound absorption These are related to _________ Foams

Aluminum

______ and _______ alloys are Stronger at subzero temperatures than at room temperature ex: cookware, cans

Aluminum and Aluminum Alloys

Lithium is the lightest of all metallic elements Each percent of Li reduces the weight by 3% and increases stiffness by 6% Light weight without compromising strength and stiffness Fracture toughness, ductility, and stress corrosion resistance are lower these are related to ______-_______alloys

Aluminum-Lithium

Other Copper-Based Alloys are _____-______ and ______-______ and ________- _______.

Aluminum-bronze Silicon-bronze Copper-beryllium

Plastic deformation below the recrystallization temperature Advantages as compared to hot working No heating required Better surface finish Superior dimensional control Better reproducibility Strength, fatigue, and wear are improved Directional properties can be imparted Contamination is minimized These are related to ______ Working

Cold

Low temperature properties are better than most other materials Nonmagnetic Nonpyrophoric Nonbiofouling Wide spectrum of colors These are Characteristics of _____

Copper

High electrical thermal conductivity Useful strength high ductility Corrosion resistance Heavier than iron These are related to ____ and _____ Alloys

Copper / Copper Alloys

Copper is the base metal Standardized by the Copper Development Association (CDA) Common alloying elements Zinc, Tin, Nickel These are related the _____-_____ Alloys

Copper-Based

Copper and nickel exhibit complete solubility High thermal conductivity High temperature strength Corrosion resistance to a range of materials High resistance to stress-corrosion cracking Ideal choice for heat exchangers Cupronickels contain 2 to 30% nickel Nickel silvers contain 10 to 30% nickel and 5% zinc Constantan contains 45% nickel 67% nickel is known as Monel used in cookware these are related to _____-_____ Alloys

Copper-Nickel

Tin is more cost effective than zinc Alloys with tin (typically < 12%) are known as tin bronzes Bronzes have desirable mechanical properties Often used for bearings, gears and fittings with high compressive loads Good strength Good toughness these are related to _____-_____ alloys

Copper-Tin

Zinc is the most common alloy addition( Known as brass) Alpha brasses, Two-phase brasses Brasses have good corrosion resistance Cold-worked brass is usually stress-relieved to remove residual stresses Lead can be added to increase machinability Cast brass has good fluidity Alloy with 50-55% Cu and remainder Zn is used as filler metal in brazing these is related to ______-______ Alloys

Copper-Zinc

________ ______ are those that are determined by the independent variable selection Force or power requirements Material properties of the product Exit or final temperature Surface finish and precision Nature of the material flow

Dependent Variables

resistance to sliding along an interface Resistance can be attributed to: Abrasion Adhesion Resistance is proportional to the strength of the weaker material and the contact area These is related to _________

Friction

Properties of metals and nonmetals Good thermal and electrical conductivity Can withstand high temperatures Lubricant Used as electrodes in arc furnaces Improvements make it suitable for use as rocket-nozzle inserts Graphite fibers used in composites Permanent molds for casting strength goes up with high temp These are related to _________

Graphite

Plastic deformation of metals at a temperature above the recrystallization temperature Temperature varies greatly with material Recrystallization removes the effects of strain hardening Hot working may produce undesirable reactions from the metal and its surroundings Engineering properties can be improved through reorienting inclusion or impurities During plastic deformation, impurities tend to flow along with the base metal or fracture into rows of fragments These are related to ______ Working

Hot

_______ ______ are the aspects of the processes that the engineer or operator has direct control Starting material Starting geometry of the workpiece Tool or die geometry Lubrication Starting temperature Speed of operation Amount of deformation

Independent Variables

Independent-Dependent Relationships _________ control is direct and immediate _________ control is entirely indirect

Independent variables / Dependent variables

Deformation that occurs under constant temperature Dies and tooling are heated to the same temperature as the workpiece Eliminates cracking from nonuniform surface temperatures Inert atmospheres may be used These are related to _________ Forming

Isothermal

High density Among the lowest strength and stiffness values of the engineering metals Storage batteries, radiation absorption Good corrosion resistance, low melting point, ease of casting or forming ex: low acid batteries These are related to ____ alloys

Lead alloys

Key to success in many metal forming operations Primarily selected to reduce friction and tool wear, but may be used as a thermal barrier, coolant, or corrosion retardant Other factors Ease of removal, lack of toxicity, odor, flammability, reactivity, temperature, velocity, wetting characteristics These are related to ________

Lubrication

Lightest of commercially important materials (2/3 of Al) Poor wear, creep, and fatigue properties Highest thermal expansion of all engineering metals Strength drops when temperature reaches 100°C (200°F) Low modulus of elasticity requires thick parts (less than Al) Most alloys have low ductility (Mg has HCP structure) High strength to weight ratio High energy absorption and good damping Used in applications where light weight components are the primary concern ex: auotmotive,power tools These are related to ______ and ______ alloys

Magnesium and Magnesium Alloys

Amorphous metals are formed by cooling liquid metal extremely quickly (105 to 106 °C/sec) so that no crystalline structure can form New developments: bulk metallic glass(liquid to glass) High strength, large elastic strain, good toughness, wear resistance, magnetic, corrosion resistance These are related to _______ Glasses

Metallic Glasses

Outstanding strength and corrosion resistance at high temperatures Wrought alloys are known as Monel, Hastelloy, Inconel, Incoloy, and others Good formability, creep resistance, strength and ductility at low temperatures Can be used in food-processing industries, turbine blades Monel (67% Ni and 30% Cu) probably has better corrosion resistance to more media than any other alloy These are related to ____ based alloys

Nickel Based Alloys

Simulations are created using finite element modeling(FEA-finite element analysis) Models can predict how a material will respond to a rolling process, fill a forging die, flow through an extrusion die, or solidify in a casting Heat treatments can be simulation Costly trial and error development cycles can be eliminated These are related to _______ modeling

Process

Surface wear is related to friction Wear on the workpiece is not objectionable, but wear on the tooling is Tooling wear is economically costly and can impact dimensional precision Tolerance control can be lost Tool wear can impact the surface finish These are related _____ _________

Surface Deterioration

Used as a corrosion resistant coating on steel Used with lead Solder Bearing materials These are related to _____ alloys

Tin alloys

Titanium is a strong, lightweight, corrosion resistant metal Properties are between those of steel and aluminum Can be used in high temperature applications High energy costs for fabrication Fabrication methods: casting, forging, rolling, extrusion, welding Abundant material, but is difficult to process from ore Three categories: alpha-, beta-, alpha-beta-titanium alloys medical implants, bicycles, heat exchangers, chemical process equipment are common uses These are related to ____ and___alloys

Titanium and Titanium Alloys

Deformations produced at temperatures intermediate to cold and hot working Advantages Reduced loads on the tooling and equipment Increased material ductility Possible reduction in the number of anneals Less scaling and decarburization Better dimensional precision and smoother surfaces than hot working Used for processes such as forging and extrusion These are related to ______ Forming

Warm