Sanket Subham Kar_Seminar and Technical writing

Presentation submission for a College assignemnt.

1. SEMINAR AND TECHNICAL WRITING TOPIC: ADDITIVE MANUFACTURING OF CERAMICS PRESENTED BY : Sanket Subham Kar ROLL NO. : 120CR0841 PRESENTED TO : Prof. Debasish Sarkar

2. WHAT IS ADDITIVE MANUFACTURING ? P rocess of joining materials to make objects from three-dimensional (3D) model data, usually layer by layer, as opposed to subtractive manufacturing and formative manufacturing methodologies. Here’s how the process takes place: Design: First , someone creates a design using computer-aided design (CAD) software or by scanning an existing object they want to print . Layer-by-Layer Process : Software translates the design into a layer-by-layer framework for the additive manufacturing machine to follow. The 3D printer then begins creating the object immediately . Materials : Various materials such as polymers, metals, ceramics, foams, gels, and even biomaterials are used. Methods : One common method of the many methods used for this that it uses a nozzle to lay successive layers of material on top of each other until the final product is complete. Another approach involves using powders (typically made from metal) and melting specific parts of the powder to form a solid part layer by layer.

3. IN THE FIELD OF CERAMICS MANUFACTURING PROCESSES CERTIFIED BY ISO/ASTM SINGLE STEP MULTI STEP NOT (YET) CLASSIFIED BY ISO/ASTM Directed energy Deposition Power bed fusion Vat phot-polymerization Material jetting Material extrusion Sheet Lamination Binder Jetting Electrophoretic depostion Electro-photographic printing

4. SINGLE STEP AND MULTI-STEP SINGLE STEP MULTI STEP The strength of a ceramic part is determined by its largest flaw. The statistical nature of the strength of ceramics is usually handled by the use of Weibull statistics, where the Weibull modulus ‘m’ describes the flaw size distribution and is a measure for the controllability of the ceramic production process. For various AM processes, Cracks are still the most critical flaws that compromise the mechanical strength. Except for non-structural ceramic parts where part strength is not a major issue (e.g. for the production of scaffolds), pores can be considered as the second largest flaws. It is important to incorporate colloidal processing techniques into the AM process as it leads to an improvement of the density and quality of the final ceramic components. Does not use a binder material , therefore does not require the time consuming binder removal step. In direct energy deposition and single step powder bed fusion processes, thermal cracks are generally caused by thermal shocks introduced by the laser-beam heating Uses a binder due to which it is able to produce different types of ceramics. In this process, cracks are generally caused during the furnace treatment. How to consider the quality of the parts used in this process ?

5. METHODS OF ADDITIVE MANUFACTURING DIRECTED ENERGY DEPOSITION Process in which focused thermal energy is used to fuse materials by melting as they are being deposited. Two kinds: Traditional DED:- The printing head of a directed energy deposition system consists of a nozzle that feeds ceramic powder particles to the focal point of a laser beam. The powder melts and solidifies on a substrate. Hybrid fused deposition modelling DED:- During an experiment a t the University of Birmingham, the scientists managed to combine the FDM(fused deposition modelling) and the directed energy deposition process into a hybrid process. Ti6Al4V-TiC composite parts could be fabricated by feeding powder ( TiC ) and wire (Ti6Al4V) material into the focus of a CO2 laser. Process in which liquid photopolymer in a vat is selectively cured by light-activated polymerization. During stereolithography (SLA) of ceramics, different ceramic-containing slurry layers are scanned by (UV) radiation that causes a chemical reaction which results in the polymerization, i.e. chemical gelling, of the slurry layers with incorporation of the ceramic particles. After debinding the resulting polymer and sintering the structural material in a furnace, the final ceramic part is obtained. The extent of the photopolymerization reaction during laser irradiation can be described with the following equation: δ c = Dp · ln(E1/ E2) VAT PHOTO-POLYMERIZATION δ c -> cured depth E1 ->energy density delivered at the surface of the resin E2 ->the critical energy density of photopolymerization Dp ->the penetration or sensitivity of the laser beam

6. METHODS OF ADDITIVE MANUFACTURING ? MATERIAL JETTING Process in which droplets of build material are selectively deposited. Two kinds : Direct Inkjet Printing:- A suspension containing ceramic powder particles is deposited (directly) from a print nozzle. The print nozzle selectively deposits individual droplets of the suspension onto a substrate. Upon contact, the droplets undergo a phase change, creating a solid part. Aerosol Jet Printing:- Uses a focused aerosol, i.e. a suspension of droplets containing fine ceramic particles in a gas. P rocess in which material is selectively dispensed through a nozzle or orifice Two kinds : Fused Deposition of ceramics:- Ceramic particles are first densely (up to 60 vol %) dispersed into a thermoplastic (or wax) filament. Layer by layer, the flexible filament is partially melted and extruded from a moving deposition head onto a static worktable. Robocasting:- a concentrated sol is extruded through a nozzle to form a filament that is directly deposited in a controlled pattern to assemble complex, three-dimensional structures in a layer-by-layer sequence. In contrast to FDC, no polymer material is (partially) melted. MATERIAL EXTRUSION

7. METHODS OF ADDITIVE MANUFACTURING SHEET LAMINATION A lso called Laminated Object Modelling (LOM) process in which sheets of material are bonded to form an object. Two kinds: Traditional LOM:- C onsists of a system that deposits green ceramic tape-cast layers. These layers are unrolled onto the working bed where a CO2 laser cuts the outline of each layer of the part. A heated roller is passed over the layer to thermally activate the tape‘s binder system and to laminate the sheet to the previous layer. Computer-Aided Manufacturing of Laminated Engineering Materials (CAM-LEM) :- This p rocess is identical to that of LOM, but instead of the layers being stacked and then cut, each layer is pre-cut and robotically stacked onto the working part for lamination. BINDER JETTING Process in which a liquid bonding agent is selectively deposited to join powder material Two kinds: 3DP of dry powder agglomerates(P-3DP):- Sequential depositing of powder particles with a roller or scraper system and printing of binder material by ink-jet printing yield the layers, resulting in a solid part. After binder burnout and sintering, a consolidated ceramic part is obtained. Slurry-based three-dimensional printing (S-3DP):- During S-3DP, each powder bed layer is created by jetting ceramic slurry onto a substrate. The ascast layer is subsequently dried and a binder is selectively deposited in the desired pattern to cement the ceramic particles.

8. METHODS OF ADDITIVE MANUFACTURING POWDER BED FUSION Multi step/Single step Single Step Multi-Step Full melting Partial melting Solid state sintering Chemically induced binding Gelling Partial melting Conven-tional Powder deposition mechanism Slurry coater Aerosol assisted spray depostion Slurry sprayer Slurry coater Ring blade Conven-tional Electro- phoretic deposition Conven-tional Conven-tional Ring blade Slurry coater Conven-tional Slurry coater Slurry coater Binding Mechanism

9. METHODS OF ADDITIVE MANUFACTURING (Not classified by ISO/ASTM) ELECTROPHORETIC DEPOSITION ELECTRO PHOTOGRAPHIC PRINTING Charged colloidal particles suspended in a liquid medium migrate (electrophoresis) and are deposited in a controlled manner to shape a three-dimensional part using an electrical field created between electrodes. A photoreceptor plate, containing an electrostatic image of the part layer, is aligned over a powder bed. The electrostatic charge causes the powder to be attracted to the plate in the exact shape of the part layer (or the negative shape of the part layer if support material has to be printed). After sequentially charging and depositing powder layers, the printed layers are compacted and sintered to produce the ceramic part.

10. APPLICATIONS 3D interdigitated microbattery architecture Comparison of the energy and power densities of printed, unpackaged 3D interdigitated microbattery architectures (3D‐IMA) to reported literature values BATTERIES SUPER CAPACITORS M anufacturing strategy developed for G aerogel/MnO2 pseudocapacitive electrodes. Capacitance versus thickness of thick electrodes at various mass loadings

11. APPLICATIONS PIEZORESISTIVE AND PIEZOELECTRIC CERAMICS AS ENERGY HARVESTERS AND SENSORS SMART GLASS Barium titanate 3D printed by stereolithography Piezoresistive response of a polymer derived SiOC upon dynamic loading conditions; the resistivity of the sample (dashed line) exhibits a precise response to the load (continuous line) Glass-ceramic composite scaffold produced by binder jetting and subsequent sintering of a cube M icron-scale silica glass objects (diameter ~ 0.5 mm) produced by two-photon DLW(Direct Laser writing) from a photoresponsive precursor resin

12. APPLICATIONS THERMOELECTRICS HEAT EXCHANGERS The typical process for traditional manufacturing of thermoelectric modules involves multiple steps, including formation of an ingot, dicing, and assembly Thermoelectric elements of varying shapes printed with fused filament fabrication A complex lattice heat exchanger configuration LCM printing of alumina heat exchanger parts with extended surfaces

13. APPLICATIONS FUTURE OF ADDITIVE MANUFACTURING IN MEDICAL TECHNOLOGY Path III : Product Evolution Strategic Necessity: Balance of growth, innovation & performance Key: Increased product functionality Market responsiveness Zero cost of increased complexity Path IV : Business Model evolution Strategic Necessity: Growth and Innovation Key: Mass customization Customer Empowerment Manufacturing at the point of use Path I : Stasis Strategic Necessity : Performance Key: Design and Rapid prototyping Production and custom tooling Low rate production Path II : Supply Chain evolution Strategic Necessity : Performance Key: Manufacturing close to place of use Responsiveness and flexibility Management of uncertain demand No Product change No Supply chain change High Supply chain change High Product change No Product change No Supply chain change High Supply chain change High Product change No Supply chain change High Supply chain change High Product change