Materials + Data Sheets

Advanced 3D Printing

Tension

 a “pulling” force 

• Apply force on both ends of an object, you are putting it in a state of tension 

• Apply force = reaction from object 

• Stretch

Compression

A pushing force 

• Apply force by pushing both ends of an object 

• Apply forces = material compresses

Flexural Force

• A combination of tension and compression 

• Bend

• Ex: Aluminimum is a good flexural force → airplane wing shaking

Anisotropic

• (of an object or substance) having a physical property that has a different value when measured in different directions. A simple example is wood, which is stronger along the grain than across it.

•  Applies in Fused Deposition Modeling (FDM) some parts of the material are stronger than others based on how the material was built.

• “Go with the grain” - Big Z, Surf’s Up (2007)

Tension load normal to layers

Part is weak

Tension load parallel to layers

Part is strong

Bending Load normal to layers

Part is strong

Bending load parallel to layers

Part is weak

Polymerization

The process of reacting monomer molecules together in a chemical reaction to form polymer chains or three dimensional networks. 

Isotropy

The characteristic where a material's properties (like tensile strength and stiffness) remain the same across the X, Y, and Z axes.

Stress

• The response of a material to force is dependent on the cross sectional area of the object being tested. Represented by the SIGMA symbol (σ)

• Stress is the force 

• Stress is calculated by dividing the force applied by the area cross section. 

Strain

• The response of a material to stress is a deformation. We call this deformation strain. Represented by the EPSILON symbol (ε)

• Strain is the reaction to the force (stress) 

• Refer to the stress and strain curve (strain X + stress Y) 

• Strain is calculated by dividing the length of the elongation by the original length of the sample. 

Proportional limit of stress/strain

• All materials will yield

• Stress is proportional to strain at this point

Before the proportional limit (yield) is known as the …

Elastic region

Elastic Deformation

Force causes material to become elastically deformed and then snap back to their original form.

After the proportional limit (yield) is known as the …

Plastic region

Plastic Deformation

Force causes a shift to the crystalline structure of our solid, leading to a fracture/material failure. 

What material does the yellow curve represent?

Glass/ceramic

What material does the blue curve represent?

Metal

What material does the green curve represent?

Plastic

Ductility

• Ductility describes how much a material can deform under tensile stress before fracturing.

• Highly ductile materials can stretch or bend significantly, while brittle materials fracture with little deformation.

• Material Breaks at the end of the stress/strain curve → Fracture Strain AKA ductility