The material for an engineering product or application is it important to understand the mechanical properties of the material. The mechanical properties of a material are those which affect the mechanical strength and ability of a material to be molded in a suitable shape. Some of the typical mechanical properties of material include:
• Strength
• Toughness
• Hardness
• Hardenability
• Brittleness
• Malleability
• Ductility
• Fatigue
Strength:Strength is the mechanical property that enables a metal to resist deformation load. The strength of a material is its capacity to withstand destruction under the action of external loads. The stronger the materials the greater the load it can withstand.
Toughness:It is the ability of a material to absorb energy and gets plastically deformed without fracturing. Its numerical value is determined by the amount of energy per unit volume. Its unit is Joule/ m3. The value of toughness of a material can be determined by stress-strain characteristics of a material. For good toughness, materials should have good strength as well as ductility.
Hardness:The resistance of a material to force penetration or bending is hardness. The hardness is the ability of a material to resist scratching, abrasion, cutting or penetration. Hardness indicates the degree of hardness of a material that can be imparted particularly steel by the process of hardening.
Hardenability: It is the ability of a material to attain the hardness by heat treatment processing. It is determined by the depth up to which the material becomes hard. The SI unit of hardenability is meter (similar to length). Hardenability of material is inversely proportional to the weldability of material.
Brittleness: The brittleness of a material indicates how easily it gets fractured when it is subjected to a force or load. When a brittle material is subjected to stress it observes very less energy and gets fractures without significant strain. Brittleness is converse to the ductility of the material. The brittleness of the material is temperature-dependent. Some metals which are ductile at normal temperature become brittle at low temperature.
Malleability: Malleability is a property of solid materials which indicates how easily a material gets deformed under compressive stress. Malleability is often categorized by the ability of a material to be formed in the form of a thin sheet by hammering or rolling. This mechanical property is an aspect of the plasticity of the material. The malleability of material is temperature-dependent. With rise in temperature, th
Ductility: Ductility is a property of a solid material indicates that how easily a material gets deformed under tensile stress. Ductility is often categorized by the ability of a material to get stretched into a wire by pulling or drawing. This mechanical property is also an aspect of the plasticity of material and is temperature-dependent. With rise in temperature, the ductility of material increases.
Fatigue: Fatigue is the weakening of a material caused by the repeated loading of the material. When a material is subjected to cyclic loading, and loading greater than a certain threshold value but much below the strength of the material (ultimate tensile strength limit or yield stress limit), microscopic cracks begin to form at grain boundaries and interfaces. Eventually, the crack reaches to a critical size. This crack propagates suddenly and the structure gets fractured. The shape of the structure affects the fatigue very much. Square holes and sharp corners lead to elevated stresses where the fatigue crack initiates.
