Materials Properties and SS-2024f

A face-centered cubic (fcc) lattice structure is a type of crystal structure where atoms are located at each of the corners and the centers of all the faces of the cube.

Tensile strain is the extension divided by the original length parallel to the extension.

This form of iron is known as martensite.

Stainless steels, Co-based alloys, and titanium-based alloys.

Bone microfractures can lead to increased risk of larger fractures, pain, and may contribute to conditions like osteoporosis if not addressed.

Pitting corrosion is a form of localized corrosion that penetrates into the metal quickly, usually at a 90-degree angle to the surface, resembling wood worm holes.

Crevice corrosion is a localized corrosion that occurs in a crevice formed between two surfaces, one of which is metal, often related to pitting corrosion.

Secondary bonds are weaker bonds such as Van der Waals bonding (in polarized molecules) and hydrogen bonding (e.g., in DNA).

Fatigue failure can be prevented through design modifications, material selection, surface treatments, and regular maintenance.

Bulk properties refer to the characteristics of a material that are observed when a large volume of the material is considered, such as density, thermal conductivity, and mechanical strength.

There is a high risk of corrosion when chromium drops down to less than 9% at the boundary.

To ensure that the devices can withstand cyclic stresses without failing during use.

The extra-cellular environment is a chemically aggressive space.

Factors influencing fatigue life include material properties, surface finish, loading conditions, and environmental factors.

Young's modulus

The primary chemical structure consists of primary bonds, which include ionic bonding (e.g., NaCl), covalent bonding (e.g., H2O), and metallic bonding (e.g., Au).

Young's Modulus (E)

To determine the mechanical properties of materials, such as strength, ductility, and toughness.

Grain refinement, solid solution strengthening, and strain hardening.

Ductile materials can undergo significant plastic deformation before rupture.

The chemical composition of a surface determines its interactions with liquids, influencing properties like wettability and adhesion.

Machining (CNC), melt casting, forging, hot isostatic pressing, and 3D printing.

Typically, it is important to match the mechanical properties of tissue with the mechanical properties of metal.

A process by which structures fail as a result of cyclic stresses.

Fretting corrosion is the deterioration at the interface of two contacting surfaces under load, accelerated by relative motion that produces slip.

Metallic biomaterials are commonly used for implants and prosthetics in medical applications due to their strength and biocompatibility.

Dislocations allow for plastic deformation to occur at lower stress levels.

Elastic constants are material properties that describe the relationship between stress and strain.

Microstructure refers to the arrangement of crystal grains, typically observed at scales of 1 μm and above.

τ = G γ, where τ is shear stress, G is shear modulus, and γ is shear strain.

760 MPa

A body-centered cubic (bcc) crystal structure with very small amounts of carbon is typically associated with low-carbon steel.

Surface properties pertain to the characteristics of a material at its surface, including surface energy, wettability, and adhesion.

Bone microfractures are typically caused by repetitive mechanical loading, inadequate rest, or underlying bone density issues.

Cold working is preferred for applications requiring high dimensional accuracy and surface finish, such as in the production of precision components.

The stages of fatigue failure include crack initiation, crack propagation, and final fracture.

Hooke's law states that extension is proportional to load.

The properties of the bulk are determined by the primary and secondary bonding structures, as well as the microstructure and higher order structures.

Roughness can enhance or reduce wettability, affecting how liquids spread or bead on a surface.

The higher order structure can significantly influence mechanical, thermal, and electrical properties, as it affects how materials respond to external forces and environmental conditions.

190 GPa

The refractive index is a measure of how much light is bent, or refracted, when entering a material.

Structure determines the properties and behavior of materials, influencing their strength, durability, and performance in various applications.

Grain structure refers to the arrangement of grains in a material, while crystalline structure refers to the ordered arrangement of atoms within a single grain.

Fatigue is the process by which a material experiences progressive and localized structural damage when subjected to cyclic loading.

Increased surface roughness can act as stress concentrators, reducing fatigue strength and life.

Tensile stress is the force divided by the area perpendicular to the force.

[GPa] or [psi]

Surface modification can enhance biocompatibility and reduce corrosion rates in metallic biomaterials.

Pitting corrosion is a localized form of corrosion that leads to the creation of small holes or pits in the material, often due to the presence of chlorides.

Yes, higher order structure can be manipulated through processes such as heat treatment, alloying, and mechanical working to enhance material properties.

Brittleness is the tendency of a material to fracture without significant deformation, while toughness is the ability of a material to absorb energy and deform plastically before fracturing.

Logic, synthesis, processing, structure, performance/application, and properties.

Corrosion, wear, and fatigue are critical failure mechanisms to consider.

A grain boundary is the interface between two grains in a polycrystalline material, where the crystal orientation changes.

Cracks usually start at a stress concentrator or stress riser.

Stress is directly proportional to strain, described by Hooke's Law.

Common metals used include titanium, stainless steel, and cobalt-chromium alloys.

σ = E ε, where σ is stress, E is Young's modulus, and ε is strain.

E represents Young's modulus, which measures the elastic stress.

Crevice corrosion is caused by the accumulation of corrosive agents in confined spaces, leading to a localized breakdown of the protective oxide layer.

Techniques such as X-ray diffraction, electron microscopy, and atomic force microscopy are commonly used to analyze higher order structures.

896 MPa

Tensile, Compression, Bending, Torsion/rotation.

Cost needs to be considered to ensure the implant is economically viable.

Engineering tensile strain is represented by ε and engineering tensile stress is represented by σ.

Stress is the normalized load, calculated as force divided by area.

Fatigue refers to the weakening of a material caused by repeatedly applied loads, leading to the formation of cracks and eventual failure.

A major challenge is the potential for corrosion and the release of metal ions into the body.

Galvanic corrosion occurs when two different metals are in electrical contact in the presence of an electrolyte, causing the more reactive metal to corrode faster.

Elastic materials can return to their original shape after the removal of stress.

The strength of a material is defined by its ability to withstand an applied load without failure.

The modulus of elasticity (E) can be calculated by taking the slope of the linear portion of the stress-strain curve, which represents the elastic region of the material's deformation.

Bone microfractures are small, often undetectable cracks in the bone structure that can occur due to repetitive stress or overuse.

Cold working can lead to increased hardness and brittleness, making further deformation more difficult and potentially leading to cracking.

Fatigue is the progressive failure of a material due to the application of cyclical stresses below the ultimate stress of the material, leading to crack propagation.

The stages of fatigue failure include crack initiation, crack propagation, and final fracture.

The S-N curve, or Wöhler curve, plots the relationship between the cyclic stress amplitude (S) and the number of cycles to failure (N).

σ = E ε

Electrochemical reactions are fundamental to corrosion as they involve the transfer of electrons between the metal and its environment, leading to material degradation.

E and G can be related to microstructure and bonding, as elastic strain increases when bonds are stretched.

Recoverable stress refers to the elastic deformation where the material returns to its original shape, while non-recoverable stress refers to plastic deformation where the material does not return to its original shape.

The modulus of elasticity (E) can be calculated by taking the slope of the linear portion of the stress-strain curve, which represents the elastic region. This is done by dividing the change in stress by the change in strain (E = Δσ / Δε).

Nickel and Titanium

A mixture of bcc and fcc and Ni can help to change the structure from bcc to fcc.

Physical, biological, processing, structure, properties, and performance.

Hot working allows for greater deformation, reduces the risk of work hardening, and can improve ductility, making it easier to shape metals.

Toughness is the energy required to break a unit volume of material, which can be approximated by the area under the stress-strain curve.

Unreinforced polymers and ceramics have smaller toughness, while metals and polymer matrix composites (PMCs) exhibit larger toughness.

Metallic biomaterials are good conductors in an electrolyte solution, leading to galvanic corrosion.

Pitting corrosion can lead to tanks leaking and boat engines requiring repair due to holes in the cylinder walls caused by salt water.

Strain is the normalized deformation, calculated as extension divided by original length.

Elastic deformation and plastic deformation.

Examples include flanged or threaded connections and shielded areas on metal surfaces due to deposit formation.

Hot working involves deforming metals at temperatures above their recrystallization temperature, while cold working is done at or near room temperature, leading to different mechanical properties and microstructures.

Crystals are solid materials whose atoms are arranged in a highly ordered, repeating pattern.

Shear stress is the force divided by the area parallel to the force.

Higher order structure refers to 3D arrays of atoms or molecules, typically ranging from 1 to 100 nm.

Failure analysis is the process of investigating materials that have failed to determine the cause of failure.

Typical stress/strain curves illustrate the relationship between stress and strain for materials under load.

Not specified

15 GPa

Birefringence, or double refraction, refers to the optical property of a material that has a different refractive index depending on the polarization and propagation direction of light.

Corrosion resistance is a key property that affects the performance of metallic biomaterials in the body.

Shear strain is the extension divided by the original length perpendicular to the extension.

Higher order structure refers to the arrangement of atoms and molecules in a material beyond the primary atomic structure, including the organization of grains, phases, and defects.

An elastic constant is a parameter that quantifies the stiffness of a material, such as Young's modulus or shear modulus.

Factors influencing fatigue life include material properties, surface finish, load magnitude, load frequency, and environmental conditions.

ε = ΔL / L₀

Wettability refers to the ability of a liquid to maintain contact with a solid surface, influenced by the intermolecular interactions between the liquid and the solid.

Electrical charge can influence the interaction between surfaces and liquids, affecting adhesion and wettability.

Ferroelectric properties refer to the ability of certain materials to exhibit spontaneous polarization that can be reversed by the application of an external electric field.

The primary mechanisms of corrosion include electrochemical reactions, galvanic corrosion, pitting corrosion, and crevice corrosion.

Polarizability is the ability of a material to become polarized in response to an electric field, affecting its dielectric properties.

Crystallinity refers to the degree of structural order in a solid, which can affect its surface energy and wettability.

Mobility refers to the ability of molecules at the surface to move, which can affect the dynamics of wetting and spreading.

Electrical conductivity is the measure of a material's ability to conduct an electric current.