4J36 Low Expansion Nickel-Iron Alloy Rod

I. Performance Characteristics of 4J36 Bar

4J36 bar (also known as Invar 36) is an iron-nickel-based alloy. Its core properties stem from a precise 36% nickel content, resulting in a unique low thermal expansion effect achieved through a single-phase γ structure. Specifically, it exhibits the following characteristics:

1. Ultra-low thermal expansion coefficient: Within the range of -60°C to 80°C, the linear expansion coefficient is ≤0.5×10⁻⁶/°C, approaching “zero expansion.” The expansion coefficient increases significantly above 100°C.

2. Excellent mechanical properties: In the annealed state, the tensile strength is 480-630 MPa, the elongation is ≥30%, and the hardness is ≤200 HB. It combines high strength with good ductility, making it suitable for cold forming.

3. Stability and corrosion resistance: Dimensional change is minimal over long-term use (≤1×10⁻⁴). Corrosion resistance is excellent in fresh water and oil media, but acid resistance is weak.

II. Main Applications of 4J36 Bar

1. Precision Instrument Manufacturing: Used in astronomical telescope mounts, laser interferometer bases, and other applications to ensure dimensional stability under temperature fluctuations.

2. Electronics and Aerospace: Used in satellite antenna frameworks, integrated circuit lead frames, and other applications to prevent solder joint cracking caused by thermal cycling.

3. Engineering Structural Parts: Used in ultra-long bridge expansion joints and cryogenic pipe compensators to resist thermal stress.

4. Other Applications: Used in the manufacture of magnetic components for electromagnetic equipment (such as inductors and transformers) and high-precision sensors.

III. Summary

Due to its low expansion, high stability, and ease of processing, 4J36 bar has become a core material in precision engineering and high-tech applications, particularly suitable for temperature-sensitive, high-precision applications.