Hot Isostatic Pressing Technology for Indian Test Blanket Module Fabrication

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Hot Isostatic Pressing Technology for Indian Test
Blanket Module Fabrication
Dr. G. Appa Rao
Defence Metallurgical Research Laboratory
Kanchanbagh PO, Hyderabad-500058, India.
Email gouduapparao_at_rediffmail.com
22 July 2008.
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Introduction

• Selection of appropriate materials and
  fabrication technologies for various components
  for fusion reactors relies on trade-off between
  multiple requirements which are mainly driven by
• Economic
• Safety and
• Environmental effects

• Materials
• Martensitic steels
• Non-Ferrous alloys
• Ceramics
• Vanadium alloys
• SiC/SiC Composites
• Ti and Cr alloys

• Fabrication Technologies
• Cutting and machining
• Special welding techniques
• Investment casting
• Hot isostatic pressing (HIP)

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Significance of HIP Technology

• Implementation and joining of F/M steels are an
  important
• goal due to the complex geometry of the
  blanket modules.
• Necessity for reducing the leak level and
  maintenance.
• Advanced techniques based on solid or powder
  HIP are to
• be established

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Principles of Isostatic Pressing
Pascals Law
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Hot Isostatic Pressing

• HIP is a an innovative thermal treatment
  process subjects the
• material / component to a combination of
  high pressure and
• elevated temperature
• HIP results in near theoretical density,
  uniform microstructure
• and consistent mechanical properties

HIPing Parameters Temperature 0.7 - 0.9
Tm Pressure 100-200 MPa Time
2- 4 h.
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Details of HIP Equipment
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Densification Mechanisms of HIPing

• Particle rearrangement
• Plasticity
• Power-law creep and
• Volume and grain boundary diffusion

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Stages of HIP Densification
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HIP Diagrams
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Applications of HIP Technology

• Cladding
• Diffusion Bonding
• Consolidation of Encapsulated Powder
• Densification of Metal castings
• Specialized Applications
• Medical Implants
• HIP of ultra fine Tungsten Carbide Cobalt Hard
  Metals
• Rejuvenation of Deteriorated Components
• Formation and Control of Pores
• Joining of Fusion Reactor Components

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Cost Reduction Potential for a Selected Group of
Superalloy Parts
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CIP and HIP Facilities at DMRL
(200 Dia. X 600 HT.) mm 400 MPa
(100 Dia. X 200 HT.) mm, 200 MPa 1450, 2000 ºC
(650 Dia. X 1200 HT.) mm, 200 MPa 1450ºC
(270 Dia. X 990 HT.) mm, 200 MPa 1450ºC
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HIPing of Stainless Steel Powder
G. Appa Rao and M.Kumar, Mater.Sci. and Technol.
1997
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Potential of HIP for Complex Shapes
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HIP Diffusion Bonding of Materials

• Advantages
• Similar and dissimilar material can be joined
• Complex shape can be joined easily
• Original microstructure remains intact
• ODS and FRM can be joined
• Joint integrity is better than that of
  conventional one

• Material forms for HIP bonding
• Powder-powder
• Powder-solid
• Solid -solid

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Microstructure of HIP Diffusion Bonded Materials
G. Appa Rao et. al, DMRL TR2000265 (2000)
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Mechanical Properties of HIP Diffusion Bonded
Alloys
Failure did not occur at the joint
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P/M(HIP) Diffusion Bonded Hardware (DMRL)
Prototype thrust chamber clouseout
Ni-base superalloy components
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Overview of Blanket Module Fabrication (Literature
)

• Reduced Activation Ferritic Martensitic (RAFMA)
  steel is the
• structural material for TBMs
• Fabrication concepts rely on plates with
  internal cooling channels

Main technologies for fabrication of TBMs

• Cutting and machining of semi finished products
• Joining of parts to produce the plates with
  internal channels
• Bending of cooling plates
• Heat treatment to improve the structure and
  properties

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Configuration Details of Blanket Module
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First Wall Fabrication Procedures
(a) Two-Step HIPing Method

• Involves machined grooved plates
• Use of Mo- alloy massive stiffening /
  supporting plates between
• the encapsulation and the FW/CP plates
• HIPing at low pressure to achieve bonding at
  the Interface
• Removal of encapsulation and Mo plates and
  drilling of channels
• The FW is further HIPed at high pressure to
  achieve full bonding
• Heat treatment, testing and evaluation

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(b) Single High Pressure HIPing Method / HIP
forming Process

• Involves insertion of round tubes in the
  rectangular grooves
• Ends of the tubes are welded to the plates but
  the tubes are not closed
• During HIPing, the tubes expand and conform to
  the grooves
• Mo- alloy supporting plates are not required
• Heat treatment, testing and evaluation.

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(c) Rectangular Tube (RT) Process

• Involves diffusion welding of RTs. and cover
  plates
• HIPing to improve the joint integrity
• No need for stiffening plates
• There is a scope for bending the RTs. and cover
  plates before HIPing.
• Heat treatment, testing and evaluation

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FW mock up manufactured by HIP forming ( top
parts before HIP bottom mock up after HIP,
bending and marching.
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Conclusions

• Fabrication of test blanket modules (TBMs) is a
  technologically
• challenging task
• Hot isostatic pressing (HIP) is a promising
  technology for
• fabrication of TBMs
• Considerable expertise on several aspects of HIP
  technology is
• available at DMRL to address various issues
  in this
• field
• Study on development of prototype TBM
  components can be
• taken up with the existing infrastructure.

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Thank you