MANIPULATION

Manipulation Techniques

Manipulation Techniques

Method for manipulation of microstructure and mechanical properties of ceramics and metal: spark-plasma sintering.

Commonly known as Pulsed Electric Current Sintering or Field Assisted Sintering Technique (FAST), Spark Plasma Sintering or STS is a common and highly effective way for the manipulation of mechanical properties of metals and ceramics as well as its microstructure. The process is costly and complex but the results it yields are extremely accurate and effective. In this process, a pulsed DC current is passed directly through the die made of graphite. In certain cases, like the ones which have conductive samples, the current may also be passed through the powder compact.

When the current is passed through the die, heat is generated internally. This method is much better than the conventional method of manipulation (known as Hot Pressing) in which the heat is provided to the die by external sources. Since the heat in this method is provided internally and it does not emanate outwards, it can be utilized to its maximum. In this process, extremely high heating can be achieved and subsequently, extremely high cooling can be achieved as well. Temperatures can be increased or decreased up to 1000 k/m at least. This makes the entire process of sintering extremely rapid. Due to the fast speed, the process gains the potential to 'densify' powders within minutes to its nanostructure and nanosize. At the same time, the process avoids turning the element into a rough form. The main benefit of this process is that it maintains the standard routes of densification. In this process, the main role is of the current that passes through the die (Rana, et al. 2009).

Method for manipulation of microstructure and mechanical properties of polymers: The SCORIM technique (Sheer Controlled Orientation Injection Moulding technique)

Researchers have identified that the most ideal method to manipulate the microstructure and mechanical properties of polymers is the SCORIM technique. It is a non conventional technique which involves injection moulding. It is also known as the melt manipulation technique but more popular as SCORIM. Different weight ratios of different polycarbonates blended in a matrix made of polypropylene (denoted by “PP/PC”) yield different results when using this technique. However, the technique is effective and efficient none the less. Additionally, it has been identified that the SCORIM technique of manipulation has high level of influence on the mechanical properties of polymers. Hence, the fact that it yield different results ...