Nickel 78/Boron 14/Silicon 8 Alloy,Nickel Boron Silicon Alloy,Ni14B8Si,E FORU

### **Nickel-Boron-Silicon Alloy (Ni-B-Si) - Self-Fluxing Hardfacing Alloy** #### **Overview** **Nickel 78/Boron 14/Silicon 8 Alloy** (typically designated as Ni-B-Si or NiCrBSi series) is a specialized self-fluxing nickel-based hardfacing alloy designed for exceptional wear resistance, corrosion protection, and high-temperature performance. The unique combination of boron and silicon creates a low-melting eutectic that provides self-fluxing characteristics during thermal deposition processes, while forming hard boride and silicide phases that deliver outstanding surface properties. --- #### **Chemical Composition (Weight %)** | Element | Content (%) | Function | |---------|-------------|-----------| | **Nickel (Ni)** | **Balance (~78%)** | Base matrix providing corrosion resistance and toughness | | **Boron (B)** | **3.0-4.5%** | Forms hard borides (Ni₃B, CrB); lowers melting point; improves wettability | | **Silicon (Si)** | **3.5-5.5%** | Deoxidizer; forms hard silicides; enhances fluidity and self-fluxing action | | **Chromium (Cr)** | **8.0-16.0%** | Enhances corrosion/oxidation resistance; forms hard chromium borides | | **Iron (Fe)** | **≤5.0%** | Controlled impurity; may be intentionally added for cost reduction | | **Carbon (C)** | **0.5-1.2%** | Forms hard carbides; increases hardness | | **Other Elements** | **≤2.0%** | Copper, aluminum, molybdenum for specific property modifications | *Note: The composition "Nickel 78/Boron 14/Silicon 8" appears to represent a phase composition rather than practical weight percentages. Commercial Ni-B-Si alloys typically contain 3-5% B and 3-6% Si.* --- #### **Physical & Mechanical Properties** | Property | Value / Description | |----------|---------------------| | **Density** | **7.6-7.9 g/cm³** | | **Solidus Temperature** | **~970-1040°C** (1780-1900°F) | | **Liquidus Temperature** | **~1010-1080°C** (1850-1975°F) | | **Hardness (As-sprayed)** | **45-60 HRC** | | **Hardness (Fused)** | **55-65 HRC** | | **Coefficient of Thermal Expansion** | **13.5-15.5 × 10⁻⁶/°C** (20-500°C) | | **Young's Modulus** | **180-220 GPa** | | **Bond Strength** | **>60 MPa** (to steel substrate) | | **Porosity (Fused)** | **<2%** | --- #### **Key Characteristics & Applications** **Key Characteristics:** - **Self-Fluxing Action**: Boron and silicon react with surface oxides during heating, creating a clean metallurgical bond - **Excellent Wear Resistance**: Hard boride and carbide phases (HRC 55-65) provide outstanding abrasion resistance - **Good Corrosion Resistance**: Nickel-chromium matrix resists various corrosive environments - **High Temperature Stability**: Maintains properties up to 800°C (1470°F) - **Low Thermal Stress**: CTE closely matches common steel substrates **Typical Applications:** - **Industrial Hardfacing**: Pump shafts, valve seats, extruder screws, and agricultural equipment - **Aerospace Components**: Turbine blade tips, seal surfaces, and wear rings - **Petrochemical Industry**: Valve components, pump casings in corrosive service - **Power Generation**: Boiler tube protections, turbine components - **Mining Equipment**: Crusher rolls, shovel teeth, conveyor screws - **Pulp & Paper**: Refiner plates, suction roll shells --- #### **Processing Methods** | Method | Description | Typical Coating Thickness | |--------|-------------|---------------------------| | **Oxy-Fuel Welding (OFW)** | Manual deposition using torch | 1.5-3.0 mm | | **Thermal Spray & Fuse** | Spray deposition followed by fusing | 0.5-2.0 mm | | **Plasma Transferred Arc (PTA)** | Automated high-deposition process | 2.0-5.0 mm | | **Laser Cladding** | Precision low-dilution process | 0.5-3.0 mm | --- #### **International Standards & Specifications** | Standard | Designation | Description | |----------|-------------|-------------| | **AWS A5.13** | **ERNiCr-B** | Specification for nickel-based hardfacing electrodes | | **ISO 14920** | **Ni 600** | Thermal spraying - Spraying and fusing of self-fluxing alloys | | **AMS 4775** | **BNi-2** | Nickel alloy brazing filler metal (similar composition) | | **DIN 8555** | **SG-Ni 15** | German standard for NiCrBSi welding filler materials | | **GB/T 984** | **Ni 320** | Chinese national standard for Ni-based hardfacing alloys | --- #### **Quality Control & Testing** - **Hardness Testing**: Rockwell C scale per ASTM E18 - **Bond Strength**: Tensile adhesion testing per ASTM C633 - **Microstructure**: Metallographic examination per ASTM E3 - **Porosity**: Image analysis per ASTM E2109 - **Thickness Measurement**: Micrometer or ultrasonic testing --- #### **Summary** **Nickel-Boron-Silicon Alloy** represents a premium self-fluxing hardfacing material that combines exceptional wear resistance with good corrosion protection and manageable processing characteristics. The synergistic effect of boron and silicon creates a unique self-fluxing capability that enables reliable metallurgical bonding while forming hard phases that deliver outstanding surface properties. Widely standardized across international specifications, this alloy family continues to be the material of choice for demanding industrial applications where surface durability and component longevity are critical.

Packing of Standard Packing: Typical bulk packaging includes palletized plastic 5 gallon/25 kg. pails, fiber and steel drums to 1 ton super sacks in full container (FCL) or truck load (T/L) quantities. Research and sample quantities and hygroscopic, oxidizing or other air sensitive materials may be packaged under argon or vacuum. Solutions are packaged in polypropylene, plastic or glass jars up to palletized 3217 gallon liquid totes Special package is available on request.