Review on Fabrication Methods of in situ Metal Matrix Composites

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Review on Fabrication Methods of in situ Metal
Matrix Composites

• By
• 1. Law Mei Lin B050810007 4BMFB1
• 2. Mohd Aqhairi Bin Bahari B050810175 4BMFB2
• 3. Mohamad Izzudin Bin Abdul Hamid B050810048
  4BMFB1
• 4. Noor Ayuhaan Binti Abd Lah B050910310
  4BMFB1
• 5. Rianah binti Jiren B050910060 4BMFB2
• 6. Siti Sainillah Binti Sulaiman B050910279
  4BMFB1
• 7. Nadiah Binti Jaafar B050910296 4BMFB1

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What is In Situ?

• In situ is a Latin phrase which translates
  literally to 'In position'.

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What is in situ techniques?

• Involve a chemical reaction resulting in the
  formation of a very fine and thermodynamically
  stable reinforcing ceramic phase within a metal
  matrix.

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Advantages of in situ techniques

• There is thermodynamic compatibility at the
  matrix-reinforcement interface.
• 2. Also, the reinforcement surfaces are likely
  to be free of contamination.
• Therefore, stronger matrix- dispersion
  bond can be achieved.

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Technologies

• Powder Metallurgy Method
• (Fabrication of in situ Fe/TiC)
• Liquid-Gas Reaction
• (Fabrication AlN/Al composite)
• Solid-Gas-Liquid Reaction Method
• (Formation of fine single crystal TiC platelets
  in the Al based matrix )
• 4. In situ Processed by Ingot Metallurgy
• (Fabrication of Al-TiC composites)
• 5. Plasma Metallurgy Method

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In situ Processed by Ingot Metallurgy

• What it means?
• in which the solidification process where the
  reinforcing particles are formed in situ in the
  molten alloy.
• Attractiveness
• Simplicity
• Economy
• Flexibility

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In situ Processed by Ingot Metallurgy

• Tong and Fang (1998) fabricated Al-TiC
  composites
• with refined microstructure,
• enhanced dispersion hardening of the reinforcing
  phases

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Process
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Ingot Metallurgy (Synthesis of composites)

Al (99.9) Ti (99.7)
Graphite powder (40-50 µm)
Melt in graphite-lined induction furnace with
argon gas flow.
Heated 1100 C 1200C 1h
1300 C 1400C 10 minutes
Mixture direct chill cast into ingot bars
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Diagram
Example of Ingot Metallurgy
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Rapid solidification(by chill block melt
spinning)
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Video(chill block melt spinning)
Ribbon shape
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Chemical Analysis

• The analysis of master ingots was done by the wet
  method.
• Carbon was determined by using automatic
  combustion apparatus.
• Sample is combusted in a stream of oxygen and the
  carbon of specimen is converted into CO2.
• The CO2 is fed into a measuring chamber where the
  concentration peak is detected with nondispersive
  spectrometer.
• The linear signal is integrated and displaced
  digitally after weight compensation and blank
  correction.

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AUTOMATIC COMBUSTION APPARATUS
Stream of oxygen
Chamber
Detection with a nondispersive spectrometer
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Applications
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As a general.
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Rapid Solidification Process Ex TiC
particulate-reinforced Al
Vapor phase Infiltration Ex Silica base
aerogel/transition metal composite
IN SITU MMC APPLICATIONS
Controlled crystallization Ex magnetic device
such as choke coils transfomers
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APPLICATIONS OF IN SITU

• 1) Aerospace
• In the aerospace industry, equipment on-board
  aircraft must be tested in situ, or in place, to
  confirm everything functions properly as a system
• 2) Petroleum production
• In situ refers to recovery techniques which apply
  heat or solvents to heavy oil or bitumen
  reservoirs beneath the earth's crust.
• 3) Experimental Physics
• In situ refers to a method of data collection or
  manipulation of a sample without exposure to an
  external environment.
• 4) Biology
• In situ means to examine the phenomenon exactly
  in place where it occurs (i.e. without moving it
  to some special medium).

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Additional Information
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In-Situ Polymerization

• In-situ polymerization has been used to prepare
  nanocomposites.
• Inorganic nano-particles are dispersed in
  monomer, followed by heat or other treatment of
  the reaction mixture to induce polymerization.
• Advantages of in-situ polymerization technique
• Uniform CNT dispersion in monomers
• Polymer chains grafted onto the convex walls of
  carbon nanotubes during in-situ thus CNT
  homogeneously dispersed in polymer matrix.

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• Advantages (cont.)
• 3. Important for the preparation of insoluble and
  thermally unstable polymer composites, which
  cannot be processed by solution or melt
  processing.
• 4. For preparation of polymer composites with
  high nanotube loading, in-situ provides very good
  miscibility with almost any types of polymers.

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In-Situ Polymerization Processing

• In-situ polymerization methods used to
  fabricate CNT- PMMA composites by incorporating
  CNTs during the course of polymerization of MMA.
• Basic starting materials
• Nanotubes
• MMA monomer
• Method In-situ free radical polymerization
  method involves polymerization of monomer using a
  radical initiator such as 2.2-azobisisobutyronitr
  ile (AIBN).
• CNTs are dispersed through ultrasonication in the
  prepolymer.

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• Adding CNT at prepolymer provides good dispersion
  in the low viscosity of the prepolymer.
• As the polymerization progresses, the viscosity
  of the solution increases and the polymer grows
  and wraps around the dispersed CNTs.
• Benefits
• Higher interfacial strengths as CNTs interact
  with the growing polymer, thus forming stronger
  CNT-polymer bonds via non-covalent or covalent
  interactions.
• Composites with enhanced mechanical, electrical
  and tribological were obtained.

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• For another research of MWCNT-PMMA composites
  synthesized by in-situ bulk polymerization usig
  AIBN as free radical initiator, the
  microstructure are shown in Figure A below.

Figure A Microstructure of the in-situ
facricated MWCNT-PMMA composite. The bright
masses indicates CNTs wrapped with PMMA layers
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Q A
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1. What is the criteria for reinforcement
selection?
In general, There are necessary criteria or
conditions that must be satisfied for the
selection of a ceramic as reinforcement in the
manufacture of good and standard metal matrix
composites.
Such criteria include density, melting
temperature, size and shape, elastic modulus,
tensile strength, thermal stability,
compatibility with matrix material, coefficient
of thermal expansion, and cost.
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2. Why choose Ti and Al for the In-situ
processed by Ingot metallurgy?
In general, selection of metal or its alloy as
matrix for production of MMC depends on the type,
required properties and the kind of application
where such composite is required.
From this experiment, Al based and Ti based
metal matrix composites have a high potential for
advanced structural applications when high
specific strength as well as good elevated
temperature resistance.
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3. Why the particulate reinforced MMCs are more
interesting due to their ease of fabrication,
low costs, and isotropic properties?Answer
The properties of MMCs are controlled by the size
and volume fraction of the reinforcement phase as
well by the nature of the matrix reinforcement
interface4. In traditional MMCs, wetting
between molten metal and reinforcements is often
poor. How this problem can be treated?Answer
This problem can be treated through a strongly
reactive alloying addition, such as Mg and Li and
through reinforcement coating.
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5) How do we know if MMC is a hybrid
composite? 6) What do you have in mind about in
situ hybrid composite?

• A metal matrix composite (MMC) is composite
  material with at least two constituent parts, one
  being a metal. The other material may be a
  different metal or another material, such as a
  ceramic or organic compound. When at least three
  materials are present, it is called a hybrid
  composite.
• Scientist do hybrid to pick up good qualities. So
  there are 2 things better in something they try
  to mix and make a best item. For e.g. some flower
  have good looks but no smell and other have great
  smell but dull look so they mix and try to make a
  flower with great look and smell together.
• The authors suggest that it may name as in situ
  hybrid composite because
• It can be achieved in a short processing time
• Many kinds of ceramic powder can be put into
  alloy liquid