Ag18CuP silver-based brazing alloy
Features:
1. Self-fluxing agent performance: Phosphorus deoxidizes during brazing, minimizing oxidation and eliminating the need for an additional flux. 2. Low-temperature brazing: With a liquidus temperature of approximately 645–710°C, it is well-suited for heat-sensitive components, reducing thermal distortion in the base material. 3. High electrical conductivity: The brazed joint exhibits electrical conductivity comparable to that of pure copper, ensuring stable electrical connections. 4. Excellent wettability: It provides thorough wetting on base materials such as copper and silver, resulting in dense, defect-free welds.
Application:
Packing:
Aluminum foil bag, iron drum, plastic drum, woven bag, pallet, customized packaging
Date of delivery:
Precision grinding, intelligent manufacturing technology, integrated solutions
3-15 days
key word:
Ag18CuP silver-copper-phosphorus brazing alloy
Powdered · Creamy — Available in Dual Forms Brazing flux · Low melting point · High electrical conductivity
Core Advantages of Ag18CuP Brazing Alloy
Self-fluxing agent function
At high temperatures, phosphorus forms P₂O₅, which reacts with copper oxide to produce a phosphate slag that protects the weld seam, often eliminating the need for an additional flux.
Low melting point · Wide brazing window
Both the solidus and liquidus temperatures are 645°C, with an optimal brazing temperature range of 643–686°C, making it well suited for the rapid brazing of copper and heat‑sensitive components.
High electrical conductivity
The electrical conductivity of silver–copper–phosphorus alloy brazing seams is comparable to that of pure copper, ensuring reliable electrical connections and making it suitable for conductive and grounding components.
Excellent wettability
It provides excellent wetting on base materials such as copper, brass, and silver, producing welds that are dense and free of porosity, making it particularly well suited for brazing delicate components.
Product Real-World Photos & Microscopic Morphology
SEM of Ag18CuP powder
Actual SEM image of the powder
Real-life photo of powdered brazing filler metal
Gray-black powder, packaged in vacuum-sealed aluminum foil bags or plastic canisters.
Actual photo of solder paste
Syringe/plastic can packaging, ready-to-use, with adjustable viscosity.
Ag18CuP silver-copper-phosphorus brazing alloy
Ag18CuP is a copper–phosphorus–silver brazing alloy containing approximately 18% silver, combining self‑fluxing properties, a low melting point, and high electrical conductivity. The addition of phosphorus imparts self‑reducing action on copper and copper alloys, so brazing of red copper typically requires no additional flux; the inclusion of silver enhances wettability and improves the electrical and thermal conductivity of the brazed joint. With a low brazing temperature (643–686°C), this product is well suited for rapid brazing of brass, red copper, silver alloys, and silver‑plated components, effectively minimizing base‑metal oxidation and softening in the heat‑affected zone.
Chemical Composition (wt%, powder)
| Grade | Cu | Ag | P | Solidus (°C) | Liquidus temperature (°C) | Brazing temperature (°C) |
|---|---|---|---|---|---|---|
| BAg18CuP | Bal. | 17.0-19.0 | 6.6-7.5 | 645 | 645 | 643-686 |
* Powder specifications: -200 mesh (≤75 μm); particle size can be customized.
Solder Paste Specifications
| Grade | Alloy powder content (wt%) | Binder (wt%) | Solidus (°C) | Liquidus temperature (°C) | Recommended Process |
|---|---|---|---|---|---|
| BAg18CuP solder paste | 80-90 | Margin | 645 | 645 | Automatic dispensing, screen printing, manual application |
Ag18CuP Brazing Process Reference
| Base material combination | Recommended Brazing Temperature (°C) | Flux Usage | Joint performance |
|---|---|---|---|
| Red copper–red copper | 650-680 | Usually no flux is required (self-fluxing). | The brazed joint is dense, with a shear strength of ≥180 MPa. |
| Red copper–brass | 660-690 | FB102 may be used in small quantities. | Good wetting, no porosity. |
| Brass - Brass | 670-700 | It is recommended to use FB102. | The brazed joint is bright and exhibits high strength. |
| Silver/Silver-plated parts Utilizing 650-680 | No flux or minimal flux required | Excellent wettability on silver, with no corrosion. |
* Copper brazing flux delivers excellent performance; for brass brazing, it is recommended to use a small amount of FB102 borax‑based flux. Suitable for flame, induction, and furnace brazing.
Ag18CuP vs. conventional CuP14 brazing filler metal
| Comparison item | Ag18CuP (silver-containing) | CuP14 (silver-free) |
|---|---|---|
| Wettability (on brass/silver) | ✓ Significantly superior to | General |
| Brazing seam toughness | ✓ Improved (silver enhances ductility) | Relatively brittle |
| Conductivity | ✓ Higher (Silver Contribution) | Good |
| Applicable base material | Copper, copper alloys, silver, and silver-plated parts | Copper and copper alloys |
| Cost | Moderate (18% silver content) | Lower |
Ag18CuP, while retaining the self‑fluxing characteristics of Ag18CuP, significantly enhances wettability on brass and silver‑plated substrates as well as joint ductility, making it suitable for high‑end electronic and refrigeration joints.
Typical application areas
Electronic packaging
Chip leads, relay contacts, conductive connections on circuit boards, sensor terminals
Refrigeration industry
Air conditioner/refrigerator copper tubing, condenser, evaporator fittings, compressor components
Power equipment
Circuit breaker contacts, busbars, transformer windings, grounding terminals
Jewelry manufacturing
Precision welding of precious metal jewelry, silver chain joining, and brazing of inlays.
Automotive industry
Radiator, oil cooler, sensor housing, horn connector
Precision instruments
Brazing of instrument parts, conductor components, and contact springs
Powdered brazing filler metal
- Powder can be applied directly, or pre‑placed solder tabs can be used to press the material.
- It exhibits excellent flowability, making it suitable for automated powder conveying and flame brazing.
- It can be blended with other metal powders to formulate special compositions.
- Vacuum-packed for a long shelf life.
Paste solder
- No on-site mixing of powder and adhesive is required; simply open the container and use.
- Excellent thixotropy, suitable for automated dispensing and screen printing.
- The carrier volatilizes completely, leaving minimal brazing residue.
- Viscosity is customizable to suit various process equipment.
End-to-end testing capability
Each batch of Ag18CuP powder and solder paste is tested for chemical composition (silver and phosphorus content), particle size distribution, oxygen content, flowability, and tapped density. A Certificate of Analysis (COA) is provided.
Packaging & Delivery
Welding powder packaging
Double-layer aluminum‑foil pouch or plastic bag, vacuum‑sealed, plus an iron drum or plastic drum.
Specifications: 1 kg, 5 kg, 10 kg, 25 kg
Solder paste packaging
Syringes (10 cc/30 cc/50 cc) or plastic containers (100 g/500 g/1 kg)
Refrigerate; shelf life: 6 months.
Delivery time
Fast delivery of in-stock products,
Custom solder paste shipping
Batch Traceability
Sample retained for each batch; COA report shipped with the goods.
Complete quality documentation is available.
Free sample
Provide samples
For brazing process validation
Technical Support
Provide brazing temperature profiles and optimize solder paste process parameters.
Assist customers in resolving technical issues.
Chemical composition(wt%)
Powder grade | Composition ( wt% ) | ||||
Cu | Ag | P | Melting temperature range ( °C ) | ||
BAg18CuP | Solidus | Liquidus line | |||
Bal. | 17.0-19.0 | 6.6-7.5 | 645 | 645 | |
Solder paste grade | Composition ( wt% ) | ||||
Alloy powder | Binder | Melting temperature range ( °C ) | |||
BAg18CuP | 80-90 | Margin | Solidus | Liquidus line | |
645 | 645 | ||||
Physical indicators
Application areas
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