Below are three schematic FCC unit cells exhibiting shaded p

Below are three schematic FCC unit cells exhibiting shaded planes and three high-resolution STM images (8x8 nm2) of gold (Au) planes. For each image, (a) identify the (hkl) planes and (b) draw the conventional lattice plane. The following has been covered in the laboratory. From an engineering point of view, hardness is the resistance of a material to deformation, indentation or penetration a. True b. False Hardness can be measured by hardness tests, such as Brinell, Knoop, Rockwell or Vickers. a. True b. False Fundamentally, hardness can be attributed to strong interatomic bonds and it can be defined as localized elastic deformation of the solid surface. However, the behavior of solid materials under compressive forces is rather a complex mechanism. a. True b. False

Solution

1.15----

True.

Hardness is the property of a material that enables it to resist plastic deformation, usually by penetration. However, the term hardness may also refer to resistance to bending, scratching, abrasion or cutting.

1.16----

True.

Hardness is not an intrinsic material property dictated by precise definitions in terms of fundamental units of mass, length and time. A hardness property value is the result of a defined measurement procedure.

Hardness Testing

Rockwell Hardness Test

Rockwell Superficial Hardness Test

Brinell Hardness Test

Vickers Hardness Test

Microhardness Test

Mohs Hardness Test

Scleroscope and other hardness testing methods

1.17....

True..

Elastic deformation stretches the bonds between atoms away from their equilibrium radius of separation, without applying enough energy to break the inter-atomic bonds. Plastic deformation, on the other hand, breaks inter-atomic bonds, and therefore involves the rearrangement of atoms in a solid material.