Massachusetts Institute of Technology VE RI TAS Harvard medical School Brigham and Womens/Massachusetts General Hosp. VA Boston Healthcare System 279/3.96J/BE44/HST522J MATERIALS: BONDING AND PROPERTIES M.S pector, Ph. D
2.79J/3.96J/BE.441/HST522J 2.79J/3.96J/BE.441/HST522J MATERIALS: MATERIALS: BONDING AND PROPERTIES BONDING AND PROPERTIES M. Spector, Ph.D. M. Spector, Ph.D. Massachusetts Institute of Technology Massachusetts Institute of Technology Harvard Medical School Harvard Medical School Brigham and Women’s/Massachusetts General Hosp. Brigham and Women’s/Massachusetts General Hosp. VA Boston Healthcare System VA Boston Healthcare System
CHEMICAL BONDING Primary Metallic 100 kcal/mol Covalent 200 ° IonIc 10-20 econdary van der waals 1-2 Hydrogen 3-7 Hydrophobic 1-2 Interactions
CHEMICAL BONDING CHEMICAL BONDING Primary Primary • Metallic Metallic 100 kcal/mol 100 kcal/mol • Covalent Covalent 200 • Ionic 10 -20 Secondary Secondary • van der Waals 1 -2 • Hydrogen Hydrogen 3 - 7 • Hydrophobic Hydrophobic 1 - 2 Interactions Interactions
MATERIALS WITH PRIMARY ATOMIC BONDS Metallic HHHH (Mee( electron“gmy or“ cloud”) °C:C:C:C -metals 100 kcalmol HHHH onIc Covalent (attraction (Shared- pair electrons oo of positive polymers ++ and negative ions biological macromolec, -ceramIcs (eg. proteins -calcium phosphates -200 kcal/mol 10-20 kcal/mol
MATERIALS WITH PRIMARY MATERIALS WITH PRIMARY ATOMIC BONDS ATOMIC BONDS + + + + + + _ _ _ _ Metallic Metallic (electron “glue” (electron “glue” or “cloud”) or “cloud”) -metals -100 kcal/mol 100 kcal/mol C C C C C C C C H H H H H H H H H H H H H H H H Ionic (attraction (attraction of positive of positive and negative ions) and negative ions) -ceramics ceramics -calcium phosphates calcium phosphates -10 -20 kcal/mol 20 kcal/mol Covalent Covalent (shared (shared - pair electrons) pair electrons) -polymers polymers -biological biological macromolec macromolec. (e.g., proteins) , proteins) -200 kcal/mol 200 kcal/mol M M M M M e M - e - e - e - e - e - e - e - e - e - e - e - e - e -
COMPOSITION OF METALS ( % Stainless steel Cobalt chromium Titanium F Co T Cr(17-20% Cr(2730) AI(55-6.5) Ni(10-17) M0(57) V③35-4.5) Mo(2-4) Ni(2.5) Fe,C,0(0.5) C(0.03) Fe, C, Mn, Si(3. 1) Mn, P, S, Si(<2.8
COMPOSITION OF METALS (%) COMPOSITION OF METALS (%) Stainless Steel Stainless Steel Cobalt Chromium Cobalt Chromium Titanium Titanium Fe Co Ti Cr (17 -20%) Cr (27 -30) Al (5.5 Al (5.5 -6.5) Ni (10 -17) Mo (5 -7) V (3.5 -4.5) Mo (2 -4) Ni (2.5) Ni (2.5) Fe,C,O (0.5) Fe,C,O (0.5) C (0.03) C (0.03) Fe, C, Mn, Si (<3.1) Mn, P, S, , P, S, Si (<2.8)
METALS Fracture surface ………e…8x….9………… Me ( M e( e
METALS M M M M M e M - e- e- e- e- ee- e- e- ee-e-e- eM e Me- e- Fracture surface Fracture surface
METAL SURFACE Free surface Electropositive """""""" MeY e e
METAL SURFACE METAL SURFACE M M M M M e M - e - e - e - e - e - e - e - e - e - e - e - e - e - Free surface Free surface Electropositive Electropositive
FORMATION OF METALLIC OXIDE urface ee ce…… e e
FORMATION OF METALLIC FORMATION OF METALLIC OXIDE M M M M M e M - e - e - e - e - e - e - e - e - e - e - e - e - e - O = O = O = Surface Surface
THE METALLIC OXIDE (CERAMIC) SURFACE OF METALS 10nm-10um Oxide Metal
THE METALLIC OXIDE THE METALLIC OXIDE (CERAMIC) SURFACE OF METALS (CERAMIC) SURFACE OF METALS Metal Oxide 10nm -10 µ m
ORTHOPAEDIC METALS ADVANTAGES DISADVANTAGES Stainless Strength Potential for corrosion Steel Ease of manuf. High mod of elasticity Availability Cobalt- Strength High mod, of elasticity Chromium Rel. wear resist Titanium Strength Poor wear resistance Low modulus Corrosion resist
ORTHOPAEDIC METALS ORTHOPAEDIC METALS ADVANTAGES ADVANTAGES DISADVANTAGES DISADVANTAGES Stainless Stainless Strength Strength Potential for corrosion Potential for corrosion Steel Ease of Ease of manuf. High mod. of elasticity High mod. of elasticity Availability Availability Cobalt - Strength Strength High mod. of elasticity High mod. of elasticity Chromium Chromium Rel. wear resist. . wear resist. Titanium Titanium Strength Strength Poor wear resistance Poor wear resistance Low modulus Low modulus Corrosion resist. Corrosion resist
METALS FOR TJA PAST PRESENT AND FUTURE 1900-19401940-196019701980199020002010 Stainless steel Cobalt-Chromium Alloy Titanium Oxinium OxiniumB(Smith &Nephew Orthopaedics; oxidized zirconium) is the first new metal alloy in orthopaedic ery in 30 years
METALS FOR TJA: METALS FOR TJA: PAST, PRESENT, AND FUTURE PAST, PRESENT, AND FUTURE 1900 -1940 1940 -1960 1970 1980 1990 2000 2010 Stainless Steel Stainless Steel Cobalt -Chromium Alloy Chromium Alloy Titanium Titanium Oxinium Oxinium Oxinium Oxinium ® (Smith &Nephew (Smith &Nephew Orthopaedics Orthopaedics; oxidized ; oxidized zirconium) is the first new metal alloy in orthopaedic zirconium) is the first new metal alloy in orthopaedic surgery in 30 years. surgery in 30 years