What is a flux?
- florile
- 3 days ago
- 4 min read
Summary
The Science of Flushing: Beyond Just Cleaning
Brazing and chemistry: what is flux?
Brazing is a crucial step in metalworking. It's the precise moment where mechanical precision merges with thermal chemistry, irreversibly determining the final quality of a product, whether it's a luxury eyeglass frame or a fine jewelry component. At Fiprokim, we understand that the excellence of a joint is not only the result of the operator's manual skill, but also of the solid science behind its execution.
Why is flux essential?
The answer lies in thermodynamics. When metals like copper, nickel, or zinc are exposed to brazing temperatures (often above 800°C), they instantly react with atmospheric oxygen. An invisible or dark oxide barrier forms, which is chemically inert and physically obstructive. Without chemical intervention, the molten filler alloy cannot "wet" the base metal; it shrinks, forming isolated beads instead of flowing, compromising the structural integrity and aesthetics of the joint.
The products of the FIPROFLUX line are active chemical agents formulated to perform a dual simultaneous function during the thermal cycle, essential for the success of the process:
Deoxidizing and flow-promoting action: The active ingredients attack and dissolve resistant surface oxides, lowering the surface tension at the solid-liquid interface. This promotes capillary action, allowing the molten alloy to penetrate deeply into even the narrowest spaces, filling the structural voids critical to mechanical strength.
Protective action (barrier): Perhaps the most critical function for aesthetic quality. Our formulations create a protective film that resists high temperatures, sealing the metal surface from air. This prevents the reformation of oxides during heating, eliminating unsightly thermal stains and preserving the material's original shine.
Specific challenges: complex materials and "green" safety
Our experience in the heart of the eyewear and goldsmithing industrial districts has led us to focus on particularly demanding alloys such as Alpacca (copper-zinc-nickel) and Monel (copper-nickel).
The management of Alpacca and Monel
These materials, standard in the luxury and precision industries, present unique metallurgical challenges:
Tenacious oxidation: Nickel and zinc form refractory oxides that general fluxes cannot dissolve effectively.
Discoloration: Monel, in particular, is prone to deep oxidation if not properly shielded, requiring expensive post-weld polishing to restore the finish.
Flowability: The presence of zinc oxides can slow the flow of the alloy, creating irregular beads.
Safety as a priority: a concrete commitment
Beyond metallurgy, there's the chemistry of safety. Historically, effective fluxes were synonymous with toxicity, often due to high concentrations of aggressive fluorides. Today, Fiprokim's vision embraces a "Green and Organic" approach, aiming to reduce environmental impact and health risks without compromising performance. Our research has focused on developing low-hazard, non-toxic formulations for specific applications, aligning with the most stringent safety regulations and our customers' needs.
The FIPROKIM answer: the FIPROFLUX line
Choosing the flux
Choosing the right flux is a strategic decision that directly impacts production costs, finished product quality, and company safety. With its FIPROFLUX line, Fiprokim offers chemical products for process solutions.
These are the main products of the FIPROFLUX line:
FIPROFLUX 361: performance and visual control
FIPROFLUX 361 is our ultimate problem solver, formulated with boron, fluorine, and alcohol to control oxidation on Monel and nickel silver up to 800 °C.
Single-Step Efficiency: Its power is such that it allows soldering without the need for additional fluxing powders or pastes. It deoxidizes and fluxes in a single step.
Intelligent Diagnostics: Used by immersion, the product leaves a white film of borates on the part. This film acts as a pre-process quality indicator: if it appears uniform, the part is ready; if it is patchy, it indicates imperfect degreasing. This allows the operator to correct the error before soldering, saving the part.
Result: A strong and clean joint, ideal for the production of eyeglass frames where mechanical strength is imperative.
FIPROFLUX 365: aesthetic protection and performance
With FIPROFLUX 365, we offer a technical solution specifically formulated to maximize the aesthetic performance of the finished product. This highly effective solvent-based protector was developed to meet the needs of processes that do not tolerate surface imperfections.
Protective efficacy: The strength of this formulation is its ability to radically prevent discoloration and thermal oxidation on sensitive materials such as nickel silver and silver. Thanks to its targeted action, it drastically reduces the need for post-welding mechanical interventions, reducing finishing times and costs.
Application areas: It is the reference standard in the manufacturing of eyeglasses and the brazing of silver costume jewelry, sectors where brilliance and surface integrity are essential requirements for the value of the product.
FIPROFLUX 369: the brazing flux
FIPROFLUX 369 is an acidic product particularly suitable as a deoxidizer in the plumbing, installation, and electrical industries. It is particularly suitable for stainless steel.
Oxide Removal: The product is a soft soldering flux with excellent surface oxide removal properties. It is used for joints in copper, copper alloys, steel, nickel, and nickel alloys.
