Mechanical properties of materials: simple explanation of complex concepts

The ability of materials to withstand various loads without destruction and deformation is determined by their mechanical properties. When choosing steels, precision alloys, concrete, bricks, glass and other materials for industrial and construction projects, engineers and designers are guided by these characteristics, which makes it possible to guarantee the reliability, durability and safety of structures and devices.

The main mechanical properties are hardness, strength, plasticity, elasticity and impact strength. These parameters help to select the ideal materials for various tasks, ensuring strength and reliability in areas such as civil and industrial construction, space industry, aviation and mechanical engineering. In this article, we'll look at the basic mechanical properties and their practical significance.

Mechanical properties: what characteristics influence the choice of materials

Hardness determines the resistance of the material to the penetration of a harder body. This property is of particular importance for machine parts and mechanisms, in particular for gears and bearings, which must have high hardness to ensure a long service life. The methods of measuring hardness using the methods of Brinell, Rockwell and Vickers help engineers select materials with optimal characteristics.

Based on the results of the hardness measurement, it is possible to judge the quality of the heat treatment performed, as well as the degree of metal content as a result of cold rolling. Hardness values for U8A carbon tool steel are especially important, U10A.

Durability is the ability of the material to withstand destruction under the influence of external loads. There are different types of strength:

• Compressive strength — the ability to resist compressive loads is important for brittle materials (concrete, brick, ceramics).
• Tensile strength — ability to withstand tensile loads. This is especially important for a number of products manufactured at the PZPS, in particular: some text
  • for precision alloys for elastic elements 40KHNM, 36NHTYU, 17HNGT;
  • for corrosion-resistant steels 12X18H10T, 12X18N9, 12X18N9SMR, 10X17N13M3T;
  • for soft magnetic alloy 49K2FA-VI.
• Bending strength — resistance to bending loads, which is necessary when choosing wood and composite materials for construction.
• Torsional strength — the ability to withstand torque, which is taken into account when designing steel shafts and titanium implants.

Strength is measured in megapascals (MPa) and is estimated by the maximum load that the material can withstand without breaking.

Plasticity characterizes the ability of the material to deform without destruction and restore its shape after the load is removed. The main parameters of plasticity:

• Relative contraction — reducing the cross-sectional area before destruction.
• Relative elongation — percentage change in length before destruction.

Optimal ductility values are especially important for steel and alloy belts, from which parts are subsequently manufactured by stamping:

• ribbons from magnetic-soft alloys 49K2FA-VI, 27KH, 50N, 50NP, 79NM, 80NM, 81NMA;
• tapes made of electrical steel 20895, 20880, 20860, 20832, 21895, 21880, 21860, 21842;
• alloy belts with a given temperature coefficient of linear expansion 29NK, 36N, 42N;
• mild steel tapes 08PS.

High ductility is important for materials that are stamped, forged and rolled.

Firmness — the ability of the material to restore its shape after deformation. The elastic modulus (Young's modulus) shows the amount of deformation at a given stress. Imagine a spring: Young's module will show how much it deforms under load and how quickly it recovers.

Resilience is particularly important for spring steels, such as 60S2A, 65G, 70S2HA, and precision alloys used in elastic elements, for example, 40KHNM, 36NHTYU, 17HNGT.

Impact strength — the ability of the material to absorb and dissipate energy when suddenly exposed to a shock load. It measures how much energy a material can absorb before it splits or collapses. High impact strength makes it possible to effectively resist destruction upon impact, while maintaining the structural integrity and functionality of the material. This is important for structures and equipment operating in conditions where sudden mechanical effects are possible, for example, in automotive parts, sports equipment and protective coatings. Impact strength is often measured using a pendulum, which makes it possible to assess the reliability and safety of the material under extreme operating conditions.

Mechanical properties of special steels and alloys

Modern technologies require steels and alloys that can withstand extreme operating conditions. One of the key properties of such materials is heat resistance, which allows them to maintain mechanical properties and resist deformations when exposed to high temperatures. Heat-resistant and heat-resistant materials they are widely used in the aviation, energy and chemical industries, where various structural elements are subject to significant thermal and mechanical loads.

Two main parameters determine heat resistance:

• Creep limit — stress at which materials under the influence of high temperatures begin to deform under constant load. This parameter is important for steels and alloys operating under prolonged heat exposure, as it determines their ability to maintain their shape and size without significant deformations.
• The limit of long-term strength — the maximum stress that the material can withstand at high temperatures without destruction. This indicator is needed to assess the durability and reliability of alloys and steels used under conditions of constant thermal exposure.

Heat-resistant alloys based on nickel, chromium et molybdenum, as well as ceramic materials and composites that combine the advantages of various components, have:

• increased resistance to oxidation and corrosion;
• high melting point;
• the ability to maintain the original mechanical properties when exposed to extreme temperatures.

St. Petersburg Precision Alloy Plant produces high quality tape made of various heat-resistant and heat-resistant materials, such as 20X13 et HN78T, and also produces foreign analogues of Inconel 625, Inconel 718 and Inconel C-276. Due to their exceptional mechanical properties and high reliability, these materials are widely used in various industries.

PZPS also provides services on the development of new steels and alloys and technologies for their production, investigates current trends in the metallurgical industry. For cooperation, please contact us at the following phones or leave application on the site. Our experts will answer all questions in detail regarding products and enterprise services.

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