Table 7.

Advantages and disadvantages of melt foaming and powder metallurgy technique.

Fabrication Techniques	Advantages	Disadvantages
Melt foaming	The melt is easily stabilised. Suited for continuous processing, with the ability to produce bulk metal foam. Economically appealing. Lighter metal such as aluminium alloys can be easily used in fabrication process due to their lower density and non-oxidising behaviour when exposed to other gases or air comprising O2. The process is relatively simple and straightforward.	Cannot be employed to create complex shapes and structures. Products are expensive due to high cost of metal hydride. Difficult to control cell size and porosity. Thermal stresses and cracks occur in the cell walls on removal of mould from furnace or by rapid cooling.
Powder metallurgy	Complex parts can be produced near to net shape. High-quality foams are manufactured and do not require machining/finishing. It is applicable to a wide range of metals and alloys like lead, brass, Zn, etc. Pore size and porosity can be tailored by space-holder size and quantity.	Method is expensive. Approach is not instantaneous. Fabrication process is time consuming.