MATERIAL SCIENCE GUIDE
Material Properties Comparison
Choosing the perfect material for your part means understanding its fundamental properties. This guide provides a detailed comparison of common plastics and metals, highlighting their strengths and weaknesses.
Plastics Comparison Table
| Property | ABS | Polycarbonate (PC) | Nylon 12 (PA12) | POM (Delrin®) | PEEK |
|---|---|---|---|---|---|
| Density (g/cm³) | 1.04 | 1.20 | 1.01 | 1.41 | 1.31 |
| Tensile Strength (MPa) | 45 | 65 | 50 | 60 | 95 |
| Flexural Modulus (GPa) | 2.3 | 2.4 | 1.7 | 2.8 | 3.7 |
| Impact Strength (kJ/m²) | 20 (Izod Notched) | 60 (Izod Notched) | 5 (Izod Notched) | 5 (Izod Notched) | 8 (Izod Notched) |
| HDT @ 0.45 MPa (°C) | 88 | 138 | 145 | 110 | 152 |
| Key Feature | Tough, easy to finish | Unbreakable, clear | Durable, functional | Low friction, stiff | Extreme temp/chem res. |
Note: Values are typical and can vary by specific grade, fillers, and test conditions.
Metals Comparison Table
| Property | Aluminum 6061-T6 | Stainless Steel 316L | Titanium Grade 5 (Ti-6Al-4V) | Copper C110 |
|---|---|---|---|---|
| Density (g/cm³) | 2.70 | 8.00 | 4.43 | 8.94 |
| Tensile Strength (MPa) | 310 | 570 | 950 | 220 |
| Yield Strength (MPa) | 276 | 290 | 880 | 69 |
| Thermal Conductivity (W/m·K) | 167 | 16 | 7 | 391 |
| Corrosion Resistance | Excellent | Excellent (chlorides) | Excellent (immune) | Good (tarnishes) |
| Key Feature | Lightweight, machinable | Corrosion res., strong | Strength-to-weight, biocompatible | High electrical/thermal cond. |
Note: Values are typical and can vary by specific grade, heat treatment, and test conditions.
Material Properties FAQ
Which is more important, Tensile Strength or Yield Strength?
For most engineering applications, **Yield Strength** is more important. It defines the point at which a material will begin to permanently deform. Designing below the yield strength ensures your part will return to its original shape after a load is removed. Tensile strength (or ultimate tensile strength) is the absolute maximum load before the material breaks.
How does temperature affect these properties?
For most materials, strength and stiffness generally decrease as temperature increases, and vice versa. Some materials, like high-performance polymers (PEEK, Ultem) and superalloys (Inconel), are specifically designed to maintain their properties at very high temperatures, making them ideal for demanding environments.