What is packing in solid?

What is packing in solid?

The Principle of Packing in Solids: The constituent particles try to get closely packed together so that the maximum closely packed structure is attained. The maximum closely packed structure is such that the minimum empty space (void) is left.

What is hcp and CCP?

Densely packed atomic spheres exist in two modes: hexagonal closest packing (HCP) and cubic closest packing (CCP). The packing conformation of spheres into a unit cell can effect the physical, chemical, electrical, and mechanical properties of a given crystalline material.

Why hcp and CCP are preferred over bcc packing?

Both ccp and hcp are highly efficient lattice; in terms of packing. The packing efficiency of both types of close packed structure is 74%, i.e. 74% of the space in hcp and ccp is filled. And the packing efficiency of body centered cubic lattice (bcc) is 68%.

What is the value of fcc?

Similarly, in a bcc lattice, the atomic packing factor is 0.680, and in fcc it is 0.740. The fcc value is the highest theoretically possible value for any lattice, although there are other lattices which also achieve the same value, such as hexagonal close packed (hcp) and one version of tetrahedral bcc.

What is close packing give example?

Examples of fcc / ccp metals include nickel, silver, gold, copper, and aluminum. Another way of stacking these layers is to omit the “C” layers altogether – simply alternate “A” and “B”. This is also a close-packed array, but the symmetry is different.

What are the two types of two dimensional close packing?

In two-dimensional close packing, a row of closed packed spheres are stacked to obtain a two-dimensional pattern. This stacking is done in two ways: Square close packing: The second row can be placed exactly below the first row in a close packing.

How will u distinguish between HCP and CCP?

There are few types of close packed crystal structures such as HCP (Hexagonal closest packed) and CCP (Cubic closest packed). The key difference between HCP and CCP is that the repeating structure of HCP has 2 layers of spheres whereas the repeating structure of CCP has 3 layers of spheres.

What is FCC give example?

physical metallurgy. …of each face (known as face-centred cubic, or fcc). Examples of metals with the hcp type of structure are magnesium, cadmium, zinc, and alpha titanium. Metals with the fcc structure include aluminum, copper, nickel, gamma iron, gold, and silver.