Research Highlights

A novel in-situ polymer derived nano ceramic MMC by friction stir processing

  • Polymer derived in-situ metal matrix composite was developed by friction stir processing.

  • We reported PDC nano particle distribution in the copper matrix.

  • We have proposed a fracture mechanism of PDC particles in multi pass FSP of composites.

  • We have achieved five times increase in micro hardness of FSP PD-MMC.

  • We report a zero wear of friction stir processed tool first time using polymer route.

  • The composite exhibited 0.2% proof stress of 201 MPa, which is almost 2 times improvement compared to base Cu.

  • The Kocks-Mecking plot of the composite showed stage III of work hardening.

Influence of particulate reinforcement on microstructure evolution of in-situ polymer derived MMC by friction stir processing

  • Introduction of fine ceramic particles in the Cu matrix enhances the recrystallization kinetics during FSP.

  • Nanosized ceramic particles effectively pin the grain boundaries and prevented the grain growth.

  • Microstructure is characterized by equiaxed fine grains of 1–3 μm bounded by high angle grain boundaries.

Microstructure, mechanical properties and shape memory behaviour of friction stir welded nitinol

  • Solid-state welding technique called friction stir welding was employed to weld Austenitic NiTi alloy sheets of thickness 1.2mm at tool rotational speeds of 800, 1000, and 1200 rpm without loosing shape memory behaviour.

Effect of Intermetallic Content on Shear Deformation of Thin Sn-3.0Ag-0.5Cu Solder Micro-joints Between Copper Substrates

  • The growth kinetics of intermetallic compounds (IMCs) in thin Sn-3Ag-0.5Cu joints attached to Cu substrates were analyzed, and empirical kinetic laws for the growth of Cu6Sn5 and Cu3Sn in thin joints were reported.
  • By combining the shear deformation results, we inferred that increased intermetallic compound (IMC) content due to heat treatment deteriorates the mechanical properties of the joint due to the presence of disconnected incipient micro cracks.

Friction stir processing of squeeze cast A356 with surface compacted graphene nanoplatelets (GNPs) for the synthesis of metal matrix composites

  • Friction stir processing (FSP) was applied to graphene nanoplatelets (GNPs) physically compacted on the surface of squeeze cast A356 alloy to incorporate GNPs within the matrix and to improve its mechanical properties

Zn-Matrix Syntactic Foams: Effect of Heat Treatment on Microstructure and Compressive Properties

  • Glass microballoon filled ZA8 alloy matrix syntactic foams were studied for the effect of heat treatment on the microstructure, compressive properties and energy absorption capacity
  • The superior properties of syntactic foams compared to those of the conventional metal foams suggest their potential applications in marine vessels and submarine structures.

Effect of microstructure on contact angle and corrosion of ductile iron: Iron-Graphite Composite

  • Understanding the relationship between the microstructure, contact angle, and corrosion can be used to develop materials with higher contact angle and corrosion-resistant microstructures.
  • Using metal pipes that have high contact angles is desirable because artificial coatings on metal pipes can degrade over time leading to high cost of replacement and contamination to water systems.

Investigations on the influence of surface mechanical attrition treatment on the corrosion behaviour of friction stir welded NiTi shape memory alloy

  • SMAT has been applied to welded NiTi alloy to improve the corrosion behaviour.
  • Influence of duration of SMAT on the corrosion behaviour has been explored.
  • SMAT performed for 1 h has shown very high resistance to corrosion.

Evolution of In-Situ Nano-Pores during Friction Stir Processing of Polymer Derived Ceramic Reinforced Metal Matrix Composites

  • Insitu Nano-porous Polymer Derived Ceramics (PDC) can be produced in Metal Matrix Composites (MMCs) using solid state Friction Stir Processing (FSP).
  • Direct insertion of cross-linked polymer into the metal by FSP in solid state is a significant step toward inserting different chemistry of polymer precursors to generate a variety of in-situ porous structures in Polymer Derived (PD)-MMC.

Microstructure and Mechanical Properties of Friction Stir Process Derived Al-TiO2 Nanocomposite

  • A fully dense Al-TiO2 nanocomposite without any pre- or post-processing.
  • Unannealed TiO2 particles were incorporated into the aluminum matrix by FSP.

Sand casting of surface-alloyed Butterfly Valve with improved hardness and corrosion resistance by incorporating metal powders in-mold coatings

  • A cost effective in-situ surface alloying procedure was investigated in this study to increase the corrosion resistance of butterfly valves cast at industrial scale.
  • A successful attempt was made to enrich the surface of WCB steel Butterfly Valve castings by surface alloying of Ni, Cr, Fe-Mn, Fe-Si, and Mo with a maximum weight percentage of 11%, 25%, 3%, 1.5%, and 3% respectively used as the alloying elements mixed with a binding medium.
  • Post manufacturing treatment was performed on the surface-alloyed samples to improve the properties.
  • The normalized and tempered surface alloyed components exhibited an improvement in corrosion resistance as compared to substrate WCB steel, and a diffusion bond at the surface alloyed layer and base metal interface was formed. The purity of the alloying powders did not show any effect on the surface alloying of WCB steel.
  • The result demonstrated that the selective alloying of the exterior surface of components using casting is a promising low-cost technique to improve the surficial properties of WCB steel.
  • The alloying layer is continuous and compact.
Research Paper

Hot deformation characteristics and microstructural evolution of Ti-900 alloy.

  • Hot deformation characteristics of the newly developed Ti-900 alloy explored.
  • The processing map for novel Ti-900 alloy has been evaluated.
  • 900 °C temperature and 0.001 s−1 strain rate provide peak efficiency for processing.
  • Constitutive equations showed activation energy in α + β regime is 485 kJ/mol.
  • Microstructures throughout the processing regions are correlated with flow curves.
  • Reverse cladding of 304 stainless steel to LM25 aluminium alloy through die-casting
  • Reverse cladding of stainless steel to aluminium alloy is feasible with die-casting.
  • Intermetallic zone thickness increases from the edge region to the central region.
  • Elemental diffusion from stainless steel towards aluminium alloy is non-selective.
  • Every intermetallic layer is associated with a distinct intermetallic compound.
  • Fe3Al15Si2 forms instead of Fe2(Al, Si)5 on the expanse of Fe(Al, Si).