The
ability of a metal to resist deformation and fracture when subjected to
external forces under certain temperature conditions is called the
mechanical properties of the metal material.
1. Strength
Strength
represents the maximum ability of a material to resist deformation and
damage under the action of external forces. It can be divided into:
Tensile Strength: Measured by stretching the metal material into
specimens of certain specifications on a tensile testing machine. Bending Strength Compressive Strength
Since metal materials follow certain rules from deformation to destruction, tensile testing is usually used for measurement.
2. Plasticity
Plasticity
is the maximum ability of a metal material to produce permanent
deformation without destruction under the action of external forces. It
is usually expressed by the sample gauge length elongation (%) and the
sample section shrinkage (%) during the tensile test.
3. Toughness
Toughness
is the ability of a metallic material to resist damage under impact
loads. The impact test is usually used, where a metal sample of a
certain size and shape is broken under an impact load on a specified
type of impact testing machine. The impact energy consumed per unit
cross-sectional area on the fracture surface is used to characterize the
toughness of the material. Chemical Properties
The property
of metals to engage in chemical reactions with other substances is
called the chemical properties of metals. In practical applications, the
main considerations are:
Corrosion Resistance: The ability of metals to resist corrosion fatigue damage. Oxidation Resistance: Specifically refers to the stability of metals against oxidation at high temperatures.
The relationships between different metals and the compounds formed between them can also affect mechanical properties.
Physical Properties
1. Density (Specific Gravity)
Density
is calculated as P=WVP=VW in grams per cubic centimeter or in cubic
meters, where PP is the weight and VV is the volume. In practical
applications, it is important to consider the relationship between
strength and density, as well as the acoustic impedance in acoustic
testing related to nondestructive testing. The product of density and
sound speed (CC) plays a role in radiation detection, as materials with
different densities have varying absorption capabilities for radiation
energy.
2. Melting Point
The
melting point is the temperature at which a metal changes from solid to
liquid. It has a direct impact on the smelting and thermal processing of
metal materials and is closely related to the high-temperature
properties of the material.
3. Thermal Expansion
Thermal
expansion is the phenomenon where the volume of a material changes
(expands or contracts) as the temperature changes. It is often measured
by the linear expansion coefficient, which is the rate of increase or
decrease in the length of the material when the temperature changes by
1°C compared to its length at 0°C.
4. Magnetism
The
property that allows a material to interact with magnetic objects is
called magnetism, which is reflected in parameters such as magnetic
permeability, hysteresis loss, residual magnetic induction intensity,
and coercive force. Thus, metal materials can be divided into
paramagnetic, diamagnetic, soft magnetic, and hard magnetic materials.
5. Electrical Properties
Electrical
properties mainly consider conductivity, which impacts resistivity and
eddy current loss in electromagnetic nondestructive testing. Processing Properties
The
adaptability of metal to various processing methods is called
processing properties, which mainly include the following four aspects:
1. Cutting Performance
Reflects the difficulty of cutting metal materials with cutting tools (such as turning, milling, planing, grinding, etc.).
2. Forgeability
Relates
to the difficulty of forming metal materials during pressure
processing, such as the plasticity of the material when it is heated to a
certain temperature (shown as the magnitude of plastic deformation
resistance), the temperature range that allows hot pressure processing,
and the expansion and contraction characteristics, as well as the limits
of plastic deformation related to microstructure and mechanical
properties, metal fluidity, and thermal conductivity during thermal
deformation.
3. Castability
Relates
to the ability of metal materials to be cast into a desired shape,
which is manifested by the fluidity, oxidation melting point in the
molten state, the uniformity and density of the microstructure of the
casting, and the cold shrinkage rate.
4. Weldability
Refers
to the ability of metal materials to be welded together. Weldability is
manifested by the melting point, gas generation during melting,
oxidation, thermal conductivity, thermal expansion and contraction
characteristics, plasticity, and the correlation with the microstructure
of the joint and nearby materials, as well as the impact on mechanical
properties.
The above briefly sums up the major properties of
metal materials. Please feel free to reach out if you have any questions
regarding this log, or if you are looking for suitable products for
your business.