Metal Strength Chart: Properties and Processability

metal types

If you are looking for information on a metal strength chart, you have come to the right place. This blog post will discuss everything you need to know about the metal strength chart. We will cover different types of metals and their corresponding strengths. So, read on whether you are a business owner who needs to know what type of metal is best for your product or someone just curious about the topic!

The main properties of metal materials include: mechanical properties, chemical properties, physical properties, and processing properties.

i. Mechanical Properties:

The ability of a metal to resist deformation and fracture when subjected to an external force (load) at a certain temperature is called the metal’s mechanical property (also known as mechanical property).

Metal materials under load have a variety of forms; they can be static loads, also can be dynamic loads, including alone or at the same time tensile stress and compressive stress, bending stress and shear stress, torsion stress, as well as friction, vibration, shock, etc.; so measure metal material mechanical performance indicators mainly has the following items:

Strength:

Tension test

The maximum stress that a material can withstand without permanent deformation. The unit is MPa or psi (lbs / in ^ -). Metal strength includes compressive strength, shear strength, tensile strength, etc. the metal materials are made to a certain specification of the sample, and the tensile test machine is stretched until the sample is broken. The strength indicators are mainly as follows:

 

① Strength Limit:

The maximum stress at which a material can resist fracture under external force generally refers to the tensile strength limit under the action of tension and is expressed as σb. For example, the strength limit corresponding to the highest point B in the tensile test graph is commonly used in MPa. The conversion relation is as follows: 1 MPa = 1 n/m2 = KGF/was (9.8) – 1 or 1 KGF/was = 9.8 MPa.

② Yield Strength Limit:

The stress that produces a permanent deformation of 0.002 under the action of external force is called the yield strength limit and is expressed as σs. For example, in the tensile test, when the specimen reaches point C on the curve, it can be said that 0.002% of the elongation occurred under certain conditions (such as the strain rate and temperature). The yield strength limit is 0.002% offset yield strength, that is σy.

③ Tensile Strength:

Under external force, the unit area of the metal specimen elongation until the break is called tensile strength, expressed in MPa or psi. For example, in the tensile test of the metal specimen, when the elongation reaches point D on the curve, it can be said that the tensile strength has occurred under certain conditions (such as strain rate and temperature). The load ratio to the original cross-sectional area is called specific tensile strength.

Tensile strength is an important mechanical property of metals, closely related to engineering structures’ safety and reliability. Metal materials with high tensile strength are generally used in important load-bearing parts. For example, the suspension bridge cables are mainly made of high carbon steel with a tensile strength of about 1770 MPa; The prestressed concrete sleepers used in railways are made of high-strength concrete with a compressive strength of 120 ~ 140MPa and a tensile strength of about 20 MPa.

④ Compressive Strength:

Under external force, the unit area of the metal specimen elongation until the break is called tensile strength, expressed in MPa or psi. For example, in the tensile test of the metal specimen, when the elongation reaches point D on the curve, it can be said that the tensile strength has occurred under certain conditions (such as strain rate and temperature). The load ratio to the original cross-sectional area is called specific tensile strength.

Tensile strength is an important mechanical property of metals, closely related to engineering structures’ safety and reliability. Metal materials with high tensile strength are generally used in important load-bearing parts. For example, the suspension bridge cables are mainly made of high carbon steel with a tensile strength of about 1770 MPa; The prestressed concrete sleepers used in railways are made of high-strength concrete with a compressive strength of 120 ~ 140MPa and a tensile strength of about 20 MPa.

⑤ Elastic Modulus:

This is the ratio of stress σ to strain δ (the unit deformation corresponding to stress) in the elastic limit of the material, denoted by E, in MPa: E=σ/δ= TGα, where α is the Angle between the O-E line and the horizontal axis O-x on the tensile test curve. Elastic modulus is an index reflecting the rigidity of metal materials (the ability of metal materials to resist elastic deformation under stress is called rigidity).

Plasticity

impact force test

The maximum ability of metal material to produce permanent deformation without damage under the action of external force is called plasticity, which is usually expressed by the elongation of sample standard distance δ (%) (elongation δ=[(L1-L0)/L0]x100%) and the shrinkage of sample section ψ (%) in a tensile test. This is the ratio of the difference (increase) between the standard distance length L1, and the original standard distance length L0 of the sample after the specimen is pulled apart in the tensile test.

In the actual test, the same material but different size (diameter, cross-section shape – such as square, round, rectangular, and gauge length) of the tensile samples measured elongation will be different, so generally need special filling, such as the most commonly used sample with a circular cross-section, the initial gauge length of sample diameter 5 times when measured elongation is expressed as the delta 5, The elongation measured when the initial scale length is 10 times the sample diameter is denoted as δ10.

Section shrinkage ratio ψ=[(F0-F1)/F0]x100%, which is the ratio of the difference between the original cross-sectional area F0 and the minimum cross-sectional area F1 at the thin neck of the specimen after the tensile test (section reduction) and F0. In practice, the most commonly used sample with a circular section can be calculated by diameter measurement: ψ=[1-(D1/D0)2]x100%, where: D0- original diameter of sample; D1- The minimum diameter of the thin neck of the specimen after pulling. The larger values of δ and ψ indicate the better plasticity of the material.

Toughness

The ability of metal materials to resist damage under impact load is called toughness. Metal samples are usually broken under an impact load in an impact test machine. The impact energy consumed per unit cross-sectional area of the fracture is used to characterize the toughness of the material: αk=Ak/F, unit J/cm² or Kg·m/cm², where: α K is the impact toughness of the metal material, Ak is the impact work, and F is The original cross-sectional area of the fracture. Metal materials with good toughness have a small value of αK.

Some Factors That Affect The Toughness Of Metal Materials Are:

Aluminum Sheet Metal

① The Carbon Content In Steel:

The carbon content has a great influence on the toughness of steel. As the carbon content increases, the brittleness of steel increases, and the toughness decreases. For example, high-carbon steels are used for cutting tools because of their high hardness and low toughness, while low-carbon steels are used for construction because of their high toughness and low hardness.

② The Presence Of Impurities:

The presence of impurities such as sulfur, phosphorus, and manganese in steel decreases the toughness of the steel. These impurities form hard and brittle carbides instead of soft and pliable ferrite or austenite.

③ The Microstructure Of The Metal:

The microstructure of the metal also affects its toughness. For example, metals with a higher proportion of ferrite are tougher than those with a higher proportion of austenite. This is because ferrite is softer and more malleable than austenite.

④ The Rate Of Cooling:

The rate of cooling also affects the toughness of the metal. For example, steels cooled slowly have a higher proportion of ferrite and are tougher than those cooled quickly. This is because slow cooling produces a larger grain size, which results in a higher proportion of ferrite. Faster cooling produces a smaller grain size, which results in a higher proportion of austenite. Austenite is harder and more brittle than ferrite.

⑤ The Amount Of Deformation:

The amount of deformation also affects the toughness of the metal. For example, cold-worked metals are tougher than those that have not been deformed. This is because cold-working produces a higher proportion of ferrite.

⑥ The Temperature:

The temperature also affects the toughness of the metal. For example, metals become more brittle at low temperatures and less tough. This is because as the temperature decreases, the atoms vibrate less, which makes them more likely to break. At high temperatures, metals become softer and more pliable. This is because the atoms vibrate more, which makes them less likely to break.

ii. Chemical Properties

The properties of metals that cause chemical reactions with other substances are called the chemical properties of metals.

In practical applications, it mainly considers the corrosion resistance and oxidation resistance of metals (also known as oxidation resistance, which especially refers to the resistance or stability of metals to oxidation at high temperature) and the influence of compounds formed between different metals and between metals and non-metals on mechanical properties, etc.

The chemical properties of metals, especially the corrosion resistance, are of great significance to the corrosion fatigue damage of metals.

iii. Physical Properties

The properties of metals that cause chemical reactions with other substances are called the chemical properties of metals.

In practical applications, it mainly considers the corrosion resistance and oxidation resistance of metals (also known as oxidation resistance, which especially refers to the resistance or stability of metals to oxidation at high temperature) and the influence of compounds formed between different metals and between metals and non-metals on mechanical properties, etc.

The chemical properties of metals, especially the corrosion resistance, are of great significance to the corrosion fatigue damage of metals.

1. Density (specific gravity):

ρ=P/V unit gram/cubic centimeter or ton/cubic meter, where P is weight and V is volume. In practical applications, in addition, to calculate the weight of the metal parts according to the density, it is important to consider the metal than strength (the ratio of sigma b strength and density rho) to help select material related to the nondestructive testing of acoustic detection of acoustic impedance rho (density and the product of the sound velocity C) and X-ray testing medium density of different material to ray energy absorption capacity and so on.

2. Melting Point:

The temperature at which a metal changes from a solid state to a liquid state directly impacts the melting and thermal processing of metal materials and has a great relationship with the high-temperature performance of materials.

3. Thermal Expansibility:

Metal materials have a linear expansion coefficient. The linear expansion coefficient is the ratio of the change in length of the metal to the original length when the temperature changes by one degree Celsius and is represented by α (alpha). Thermal expansivity influences many aspects, such as dimensional accuracy, thermal stress, crack resistance, etc.

With the change of temperature, the volume of the material also changes (expansion or contraction) phenomenon called thermal expansion, multi-purpose linear expansion coefficient measurement, that is, when the temperature changes 1℃, the material length increase or decreases of its 0℃ length ratio.

Thermal expansibility is related to the specific heat of the material. In practical application, we should also consider the specific capacity (when the material is affected by the external environment such as temperature, the volume of the material per unit weight is increased or decreased, that is, the ratio of volume and mass), especially for the metal parts working in a high-temperature environment, or a cold and hot alternating environment, we must consider the influence of its expansion performance.

4. Magnetism:

The ability of a material to be attracted by a magnet is called magnetic. Most metals are non-magnetic, but some metals (such as iron, cobalt, and nickel) can be magnetized to form permanent magnets. The magnetism of metals is related to the electron spin in the atoms of the metal. In practical applications, we should also consider the influence of magnetism on the performance of materials, such as magnetic permeability, magnetic susceptibility, and so on.

5. Electrical Properties:

Metal materials have good conductivity, determined by the atoms’ free electrons. The electrical conductivity of different metals varies widely. Under normal circumstances, the conductivity of metals decreases with the increase of temperature and increases with the decrease of temperature.

Metal Strength Chart

Document
Materials Density (Kg/cm³) Tensile Trength (PSI) Yield Strength (PSI) Hardness Rockwell (B-Scale)
Aluminum 6061 2.72 45000 40000 60
Aluminum 7075 2.81 74,000 63000 53.5
Brass 8.73 49000 18000 55 - 73
Stainless steel 304 8.00 73200 31200 70
Stainless steel 316 7.99 84100 42100 95
Copper 8.96 30500 4830 40-50
Bronze 8.73 34800 18100
Titanium 4.5 63000 37000 70- 74
Magnesium 1.738 12000 3000 30

iV. Processing Properties

The adaptability of metal to various processing techniques is called process performance, which mainly has the following four aspects:

1. Cutting Performance:

sheet metal cutting

The cutting performance of a metal is its ability to be machined using cutting tools. (Lathe, milling machine, grinder, etc.). Metal materials are generally easier to machine than non-metallic materials. The main factors affecting metals’ cutting performance are hardness, toughness, flexibility, and thermal conductivity.

Hardness, toughness, and flexibility have a direct effect on the cutting performance of metals. The higher the metal’s hardness, toughness, and flexibility, the better the cutting performance. Thermal conductivity affects the cutting performance of metals indirectly. The heat generated during machining is quickly conducted away by metals with high thermal conductivity, which is beneficial to chip removal but not conducive to cutting.z

2. Malleability:

sheet metal surface finishes

Reflecting metal material in the process of pressure to the difficulty of the molding, such as the material is heated to a certain temperature when the plasticity of the high and low (characterized by the size of the plastic deformation resistance), allows the temperature of the thermal pressure processing size, heat bilges cold shrink characteristics related to the microstructure, mechanical properties and the critical deformation limit of the thermal deformation of metal, liquidity, heat conduction performance, etc.

3. Castability:

It reflects the difficulty of melting and casting metal materials, manifested as fluidity, suction, oxidation, melting point, uniformity and compactness of casting microstructure, and cold shrinkage rate.

4. Weldability:

sheet metal wedding

Reflect metal materials in the local rapid heating, melt combining site rapid melting or half (pressure), which combines parts tightly together and become to the difficulty of the whole, characterized by melting point, melting of inspiratory sex, oxidation, thermal conductivity, heat bilges cold shrink, plasticity and joint parts and the correlation of material microstructure, the impact on the mechanical properties, etc.

Author

Gavin Leo is a technical writer at Aria with 8 years of experience in Engineering, He proficient in machining characteristics and surface finish process of various materials. and participated in the development of more than 100complex injection molding and CNC machining projects. He is passionate about sharing his knowledge and experience.