Aluminum Alloy Substrates for Magnetic Disks
For HDD Magnetic Disks
Magnetic disks made of aluminum alloys are used in hard disk drives (HDDs) because aluminum is non-magnetic, lightweight and grindable precisely. Aluminum substrates are less expensive than glass substrates, so they are used not only in personal computers but also in home electronics such as HDD recorders.
Features
- Our optimum casting and heat treatment conditions limit intermetallic compounds and non-metallic inclusions which cause surface defects on magnetic disks.
- Excellent flatness necessary for magnetic disks is attained by our sophisticated manufacturing technology and quality control.
Product Characteristics
Chemical composition and characteristics of FP-3 alloy
Chemical composition (mass%)
Si | Fe | Cu | Mn | Mg | Cr | Zn | Ti | Al |
---|---|---|---|---|---|---|---|---|
≦0.05 | ≦0.1 | ≦0.05 | ≦0.1 | 3.5–5.0 | ≦0.1 | ≦0.5 | ≦0.1 | bal. |
Characteristics
Tensile strength (N/mm2) |
Yield strength (N/mm2) |
Elongation (%) |
Hardness (Hv) |
Specific gravity | Young's modulus (kN/mm2) |
Thermal expansion coefficient (10-6/°C) |
---|---|---|---|---|---|---|
250 | 120 | 23 | 60 | 2.65 | 72 | 24.2 |