INTRODUCTION TO PROCESSING OF BIOMATERIALS - Advanced Biomaterials: Fundamentals, Processing, and Applications - page 246

Raw materials

Crushing

VPCR

Grinding

Powders

Spray dried

Sol-Gel

Freeze drying

Mixing

Drying

Hot isotactic
processing

Pressure
fabrication

Vapor deposition

Plastic forming

Forming Injection molding

Slip casting

Gel casting

Tspe casting

Sol-Gel
processing

Sintering Hot pressing

Figure 8.3. Schematic representation of ceramic processing techniques.

preparation can have a signifi cant infl uence on the performance of the ultimate
ceramic device/implant.

8.3.2.2.2 FORMING (SHAPING) AND SINTERING OF POWDERS. The preparation
of powders culminates in the formation of a solid ceramic product. Solvent/
binder is then added to the solid ceramic product to provide a specifi c shape.
These forming processes can be broadly categorized into two types: traditional
and non-traditional (Figure 8.3). The product formed after the forming process
is known as “green ware [1].” Subsequently, this product then undergoes a heat
treatment (called fi ring or sintering) for the removal of water and binders from
the rigid fi nished product.

8.3.2.2.3 SURFACE TREATMENT. Various techniques have been developed to
alter the surface characteristics (chemistry and topography) of ceramics to im-
prove the functionality of the fi nal device. Some of the major surface modifi ca-
tion techniques include laser treatment [36], metal ion treatment [37], and acid
treatment [41]. Laser treatment can be used to alter the surface of fi nal products
obtained from ceramics for controlling thermal gradients and cooling rates, for
example, alumina-based ceramics [36]. Metal ions and their complexes can be
used for the modifi cation of ceramic surfaces, for example, Al 3+ complexes are