I. Technical Background and Industry Status

Iron-nickel fixed-expansion sealing alloys are a type of special metal materials that achieve specific expansion coefficients through precise control of nickel content, widely used in electronic packaging, aerospace, energy power, and other fields. Their core value lies in achieving thermal expansion coefficient matching with sealing materials such as glass and ceramics, ensuring the sealing and reliability of devices under extreme operating conditions. Qinchuan New Materials (Zhengzhou) Co., Ltd., as a professional enterprise in the field of special alloys in China, relies on the regional advantages of the Zhengzhou High-tech Industrial Development Zone to build a full industrial chain technical system from high-purity metal smelting to precision processing, forming a unique technical advantage in the field of iron-nickel fixed-expansion alloys.

Chapter II: Core Technology Layout and R&D Strength

1. Material composition optimization technology
Qingchuan controls the gas content in the alloy below 0.001% and the inclusion size ≤5μm through the dual process of vacuum induction melting (VIM) + electroslag remelting (ESR), ensuring the purity of the material meets international standards. Taking the 4J50 alloy as an example, its nickel content is precisely controlled within the range of 49.5%-50.5%, with an expansion coefficient (20-300℃) of (4.7±0.3)×10⁻⁶/℃，and a match with soft glass exceeding 98%.

2. Precision molding technology
In response to the demand for complex structural components in the aerospace field, Qinchuan has developed directional solidification and single crystal casting technologies, capable of producing turbine blade castings with multi-level cooling channels. Through hot isostatic pressing (HIP) treatment, micro-porous defects are eliminated, resulting in a 20% increase in the tensile strength of K418 alloy at 980°C and a 15% improvement in creep resistance.

3. Innovative heat treatment system
Employing a graded solid solution plus dual-stage aging process, the size distribution of the γ' strengthening phase (Ni₃(Al,Ti)) is precisely controlled. Experimental data show that after optimized heat treatment, the 4J54 alloy maintains a tensile strength of ≥650MPa and elongation of ≥12% at room temperature after aging for 1000 hours at 600℃.

Chapter 3: Analysis of Typical Application Cases

1. Domestic production of aviation engine turbine blades
In a certain type of aviation engine project, the K418 alloy blades provided by Qingchuan successfully replaced imported materials. By optimizing the parameters of directional solidification process (pulling speed 3mm/min, temperature gradient 100℃/cm), the first-pass pass rate of the blades increased from 65% to 92%, and the unit cost was reduced by 38%. Ground bench tests have verified that under 950℃ and 320MPa stress conditions, the blades have accumulated over 5000 hours of operation without any cracks.

2. Electronic Packaging Glass Sealing Component Development
For 5G communication base station chip packaging requirements, the UNS K94100 alloy tube shell material developed by Qingchuan has an expansion coefficient (0-100℃) of (5.2±0.2)×10⁻⁶/℃，with a matching error with borosilicate glass of ≤0.5×10⁻⁶/℃. After salt mist testing (96 hours) and thermal cycling testing (-55℃~125℃, 1000 times), the sealing detection pass rate remains at 100%.

3. Automotive turbocharger impeller mass production
The 4J50 alloy impeller developed for an international car brand achieves ±0.05mm wall thickness tolerance through precision casting and CNC machining processes. In the bench durability test, the impeller runs continuously for 2000 hours at an exhaust temperature of 1050°C, with deformation ≤0.1mm, meeting the European ACEA standard requirements. Currently, the product has a stable supply capacity of 500,000 pieces per year.

4. Technical Parameters and Quality Control System

The comprehensive quality control system established by Qinchuan covers:
- Chemical Composition: Analyzed by ICP-AES analyzer, detection accuracy up to 0.0001%
- Mechanical properties: Universal testing machine (load range 0-1000kN)
Microstructure Analysis: OLYMPUS GX51 Microscope (Magnification 50-1000x)
Non-destructive testing: X-ray real-time imaging system (resolution ≤ 2μm)
Main Product Technical Parameters:
| Brand | Coefficient of Expansion (20-300℃) | Tensile Strength (MPa) | Elongation (%) | Application Field |
|--------|----------------------|----------------|------------|------------------|
4J50 | (4.7±0.3)×10⁻⁶/℃ | ≥620 | ≥18 | Electronic packaging, glass sealed parts
| K418 | - | ≥980 | ≥8 | Aeronautical Turbine Blades |
| UNS K94100 | (5.2±0.2)×10⁻⁶/℃ | ≥750 | ≥15 | High Temperature Sensor |

5. Industry Value and Development Prospects

Qinchuan New Materials has successfully broken the foreign technology monopoly through the collaborative innovation model of "materials + technology + solutions," achieving independent control of key materials in high-end equipment fields such as aviation engines and gas turbines. Its developed iron-nickel fixed expansion alloy series products not only meet the domestic market demand but have also been exported to Europe, Southeast Asia, and other regions, accumulating 32 patented technologies and participating in the formulation of 4 industry standards. With the advancement of the "dual carbon" strategy, the company's technological layout in the hydrogen energy equipment and nuclear power fields will continue to deepen, providing stronger support for the domestic substitution of special alloy materials.