Advanced Materials-MS506(Class 1)

8/7/2019 Advanced Materials-MS506(Class 1)

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Advanced Materials-

MS506

Dr. Suhash Ranjan Dey

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Date Time Course

26 February 2011

(Saturday)02 pm to 04pm

EE 5510: Analog IC Design (EE)

CH 6240: Reacting Flows

28 February 2011

(Monday)02 pm to 04pm

EE 6020:Wireless Sensor Networks (EE)

ME 6240: Turbulence (ME)

CH 5020: Advanced Transport Phenomena (CHE)

CE 6020: Advanced Foundation Engineering (CE)

MS 5060: Advanced Materials (MSE+CHY)M Sc: CY5520: Organic Chemistry II

01 March 2011

(Tuesday)02 pm to 04pm

CS 6010: Advance Computer Networks (EE+CSE)

ME 6060: Mechatronic Systems (ME)

CE 6040: Advanced Concrete Design (CE)

MS 5040: Thermo mechanical Processing of Materials (MSE)

M Sc: CY 5540: Coordination Chemistry

02 March 2011

(Wednesday)02 pm to 04pm

EE 5370: Digital IC Design & Verifications(EE)

ME 6100: Nonlinear Oscillation (ME)

CH 6220: Advanced Solid Liquid Separation (CHE)

CE 5020: Finite Element Method (CE)

BO 6040: Advanced Biochemistry and Genetic Engineering

CS 6060: Topics in Theoretical Computer Science (CSE)

M Sc: CY 5580: Statistical Thermodynamics& Surface Science

03 March 2011

(Thursday)02 pm to 04pm

EE 5310: Information Theory (EE)

CS 6020: Computational Complexity (CSE)

ME 6220: Advanced CFD (ME)

CH 6200: Non Newtonian Fluid Mechanics (CHE)

CE 6060: Infrastructure Assessment (CE)

MS 5020: Electron Microscopy (MSE)BO 6020: Molecular & Cell Biology of Gene & Proteins

M Sc: CY 5560: Main Group Chemistry

04 March 2010

(Friday)02 pm to 04pm

CS 6080: Pattern Recognition(EE+CSE)

CH 6280: Mathematical Methods (ME+CHE)

BO 6060: Bio Instrumentation

M Sc: CY 7120: Spectroscopy & Applications

05 March 2010(Saturday)

02 pm to 04pm

CS 6040: Algorithms for VLSI(EE+CSE)

ME 6280: Compressible Fluid Flow (ME)

CY 7060: Chemical & Electrochemical Energy Systems(CY+MSE-Phd)

ME 6040: Fracture Mechanics (MSE+ME)


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Course Syllabus1. Biomaterials

a) Introduction

b) Requirements (Mechanical Properties, Biocompatibility, High

corrosion and wear resistance, Osseointegration)

c) Currently used metallic biomedical materials and their

limitationsd) Ti alloys (thermomechanical processing, microstructure and

properties, wear, corrosion behavior, surface modification)

e) Ti alloys used in Dentistry

f) Next generation biomaterials Nanophase materials

2. Energy Conversion and Energy Storage Materials

1. Energy Conversion Materials (Thermoelectric materials,

Piezoelectric materials, Solar cells)

2. Energy Storage Materials (Li-ion Batteries, Fuel Cells and

Nickel-MH batteries, Hydrogen storage) 3


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Course Structure

Mid Semester Exam 40% (28th Feb 2011)

End Semester Exam (25th Apr 30th Apr 2011)

60% Assignments (during the class and/or take

home)

Compulsory9

0% attendance

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What is this?????

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The metallic parts ofthe first artificial heart are made of titanium (ABIOMED, Inc.,

Danvers, MA, USA).


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Biomaterials

Definition: Biomaterials are artificial ornatural materials, used to in the making ofstructures or implants, to replace the lost or

diseased biological structure to restore formand function.

It helps in improving the quality of life andlongevity of human beings and the field ofbiomaterials has shown rapid growth with thedemands of an aging population.

6What are the various usages of biomaterials?????


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Various Usages of Biomaterials

Biomaterials are used in different parts of the human body asartificial valves in the heart, stents in blood vessels,

replacement implants in shoulders, knees, hips, elbows, ears

and orthodental structures.

It is also used as cardiac simulator and for urinary tract

reconstruction.

The number of implants used for spinal, hip and knee

replacements are extremely high. Human joints suffer from

degenerative diseases such as arthritis leading to pain or loss

in function. This leads to degradation of the mechanical properties of the

bone due to excessive loading or absence of normal biological

self-healing process.

Artificial biomaterials are the solutions for these problemsthrough surgical implantations7


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Total Hip Replacement

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Total hip and knee implants replacements (THR and TKR).

What are the problems that can arise from biomaterial implantation?????


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Issues with Biomaterials Implantation

9Need of the hour: Biomaterials with better quality, durable, lost cost and less painful to the patients


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Essential requirements needed to

qualify as a Biomaterial

Biomaterials must fulfill the following requirements:

a) corrosion resistance

b) Biocompatibility (?????)

c) bioadhesion (osseointegration)d) favorable mechanical properties, e.g. Youngs

Modulus, similar to that of the bone, fatigue strengthaccording to the intended application

e) processability (casting, deformation, powdermetallurgy, machinability, welding, brazing, etc.)

f) availability (low prices)

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Metals/alloys used as Biomaterials

1. stainless steel, e.g. X2CrNiMo1812 (316L)

2. CoCr-based alloys (vitallium) in the as-cast condition, e.g. CoCr30Mo6, orin the as-wrought condition, e.g. CoNi35Cr20

3. cp-titanium and titanium alloys, e.g. Ti-6Al-4V

4. cp-niobium

5. cp-tantalum

Since medical progress often makes special demands on the properties ofthe biomaterial, it has become necessary to develop tailor-made materials(metal-matrix composites based on titanium) according to the particularapplication.

Other non-metallic biomaterials: Polymers, ceramic oxides, calciumphosphates (why?????), bioactive glass ceramics

From natural sources: Bovine bone, Coral, Coralline HA,Autologous/allogenic bones, Deminerallized Bone Matrix (DBM)

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Biomaterials and their Applications

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Classification of Biomaterials based on

tissue response

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Comparison among Biomaterials

w.r.t. their Required Qualities

1. Corrosion Resistance:

Human Body Fluid contains 0.9% NaCl, pH

value 7.4. During surgery pH changes from 7.8 to 5.5

In this medium, most corrosion resistive is

titanium and its alloys, niobium and tantalum,followed by wrought and cast vitallium

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1. Corrosion Resistance

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Breaking of passivation layer by mechanical fretting (Wear) or surgical instruments, @

repassivation time is important.

Surface coating with hard layers like TiN is desirable to avoid fretting. Nitrogen ion

bombardment showed better surface properties

Oxygen adsorption on the surface through anodic or thermal oxidation also improvespassivation and fatigue properties


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Wear

Wear makes loosening of the implant joints

Wear produces wear debris from the implant into the

surrounding tissue that results in bone resorption, which

ultimately results in implant loosening

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Post mortem analysis of the patients

showed the presence of wear debris

in the liver, lymph nodes, spleen.

From the implant retrieval studies offemoral head of cobaltchrome

molybdenum (CoCr Mo), 316L

stainless steel (SS) and titanium

aluminium vanadium (Ti6Al4V)

alloy that were loosened by aseptic

loosening, it was noted that titaniumalloy femoral heads consistently had

the maximum wear averaging 74.3%

against high molecular weight

polyethylene acetabular component.

CoCr alloy was found to wear the

least and wear of SS was in betweenCoCr and Ti alloy.

Ceramics (zirconia and Alumina composite is

found having better wear resistance

properties than alloys).


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2. Biocompatibility

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Response of the human bone to an implant at different time intervals and the

various reactions occurring during cell attachment on the implant.


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2. Biocompatibility

In the implant/body system various interactions and reactions can lead to the

following injuries:

a) By the corrosion process a flow of electrons in the implant metal and a

flow of ions in the surrounding tissue is produced. This ion flow in the

tissue may disturb the physiological ion movement of the nerve cells.b) An inorganic reaction of the implant, or especially of primary corrosion

products, with a large surface by solution of metal ions in the body fluid

and transportation to various organs, where they become concentrated

and can produce systemic or hypersensitive effects if the limit of toxicity

for a certain metal is exceeded.

c) An organic, direct reaction of the implant or of the primary corrosion

products with proteins of the tissue causing an allergy or inflammation.

d) Production of H2O2 by inflammatory cells and decomposition of H2O2with the formation of a hydroxyl radical causing an injury of the

biological system.18


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2. Biocompatibility

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Physical and chemical properties of primary corrosion products of metallic biomaterials.


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2. Biocompatibility

Ti, Ta, and Nb are reported to be biocompatiblebecause they form protective surface layers ofsemi- or nonconductive oxides which preventsion flow.

This can be determined by the dielectricconstants of oxide layers.

Higher dielectric constant than water is better likeTiO2 (rutile), Fe2O3 and Nb2O5.

Lower isolating effect (dielectric constant) andtherefore higher conductivity. Eg. Al2O3, Cr2O3and Ta2O5.

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2. Biocompatibility

The primary corrosion products are particularly responsiblefor inorganic and organic reactions. These corrosionproducts have a different thermodynamic stability.

While the oxides and hydroxides of Al, Cr, Nb, Ta, Ti, and V

are stable because of a greater negative heat of formationthan that of water, the oxides and hydroxides of Co and Niare less stable so that an interaction with body fluid mayoccur.

Also thermodynamically stable corrosion products have a

low solubility (positive pK-values) in body fluid. Ti-, Ta-, Nb-,and Cr-oxides have pK-values of >14, i.e. hydrolysis doesnot feature, Co-, Fe- and Ni-oxides possess negative pK-values, which are the cause of considerable solubility.

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2. Biocompatibility

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Survival curves of L132 cells in the presence of different metal powder suspensions

Advanced Materials-MS506(Class 1)

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