4.1 4.1.1(Tensile strength) Tension test . (test specimen). Gage length l050mm (usually) A0D012.5mm Engineering stressP/A0 Engineering straine(ll0)l2 Modulus of elastisticE =/e (). 4.1.2 A.1. 2. 1.steel 2.AlCopperMnNiTiZin B.differenceexBut waker.

1. 2. but Alloy ex ex1. 2. 4.2 Structure of Alloy

or(amorphous)(ex) (crystalline)(space lattice)

Principles for complete form the substitutional solid solution. 2 metals must have similar caystal structure difference in their atomic radii should be less than 15%. Inserstitial solid solution(Solute atom size is much smaller than that of solrent atom ) ex:IronCarbon Principles for the complete interstitial solid solution. 1. Solvent atom has more than one valence() 2. atomic radius of the solute atom is less than 59% of the solvent atom. Intermetallic compounds(solute atoms are present among soluvent atom in certain proportion)bccfcchcpex:-

4.2.2ductility a. percent elongationElongation = (lfl0)l0 100 b. reduction of Areareduction of Area = (A0Af)A0 1004.2.3 True stress and true strain True stress,= P/A (A: instantaneous area) True strain,= ln(ll0) eengineering and true strain are approximately equal.edifference between then is getting largen true strain is more real to the physical phenomena.(example in textbook) 4.2.4 Construction of stress-strain curues.4.2.5 Strain at necking in a tension.4.2.6 Compression Many manufacturing processes are doing under pressure, thus compression test is very important. 50%,.For ,

4.2.7 Torsion shear stressT2r2 t shear strainrl

4.2.8 Hardness resistance to pormanent indentalion . 1. 2.

Process then adding load to Steelaluminumlead

property the resistance to indentation depends on the shape of the indenter. A. Brinell testdia10mmsteel ball with aload of 50015003000kg. HB or BHNPcurred surface area of indentation

annealing metals generally have rounded profile. Cold-worked metals have a shape profile. B. Rockwell testmeasures the depth of penstration instead of diameter of indentation. steel ballDiamondcone. C. Vickers testuse diamond pyramidload1kg120kg. unitHV or DHP. D. Knoop testdiamond pyramidload25g5kg.depth. E. Scleroscopediamond eipped indenter enclosed in a glass tubethen dropped form a castain hightmeasure the rebound of the indentor. F. Mohs hardnessone material to scratch another scale form 110 diamond. G. Durometerfor rubbersplastiesand soft and elastic material. constant load against surface measure depth after 1 secondhardness is imersaly related to the depth. H. Hot hardnessfor cutting took in machining or die in hot working. (hardness Indentor and sqecimenjurnace.

4.2.9 Fatiguerepeated loads.The part fails at a stress level below which failure would occur under Static loading mechanical componentUse various states of stresscombination of tensioncompression And torsion.canied out at various stress ainplitnele and No. of cycles.4.2.10 Creep4.2.11 Impactmay have high yield stress and hardnessbut not necessary for impact.4.2.11 Residual stressesworkpiecesdeformed4.3 Iron-Carbon System pure iron = 0.008C (up to) steel = 2.11% C cast iron = 6.67% C (most are less than 4.5%) commescially100%graphit -:information how to modofy and evaluate the properties of these important material for specific application. Ferrite(Alpha Ferrite): relatively soft and ductiletemp.768

ex: (bcc)body centered cubic. (fcc)face centered cubic. have mast density hexagonal close paclced. (allotropic) ex: have the same structure 1394(2541) 9101394(1679) but Substitutional Solid Solution orcalled substitutional solid solution. Add solute to solventalloy ex: ZincLattice of copperZinc