How do you use a brazing rod And Cold Spray?
Brazing Rod And Cold Spray is a process similar to soldering, which is useful for joining two pieces of metal together, forming a strong load-bearing joint. The primary difference between soldering and brazing is that the brazing process requires a higher temperature.
The cold spray uses material deposition of metallic and non-metallic to form a coating by consolidating the material by ballistic bombardment. The technique is a coating technology that uses solid-state coating materials to produce thick coats.
Coatings with nanostructure feature better mechanical and physical properties than the coatings that do not use nanostructure. Let’s take an in-depth look at brazing rod and cold spray.
Brazing Rod Materials
The selection of the material for making Brazing Rod And Cold Spray is dependent on a variety of criteria such as usage and base metals. The melting point of the brazing rod material must be lower than the melting point of the metal pieces undergoing a brazing process.
Brazing Rod And Cold Spray consists of generally an alloy that comprises of two or more metals with favourable properties. Rod and wire form of filler materials usually find application in manual brazing process as they are easy to use.
Steps In Brazing
There are certain things you need to ensure for getting a proper connection while brazing. You must be careful not to overheat the base metal during the brazing process. However, the complete joint area needs heating above the melting point of the brazing rod to assure that the filling material spreads uniformly and forms a strong bond.
1. Ensure Proper Fit And Clearance
Brazing distributes the molten filler metal between the base metal pieces by making use of the process of capillary action. Capillary action requires clearance between the ends of the two metal pieces to build a secure connection.
Most brazing process uses clearance in the range of 0.001 to 0.005 inch, and the optimal clearance distance is 0.0015 inch. The strength of brazing decreases with the increase in distance between the base metals and the capillary action ceases when the clearance reaches a span of 0.012 inches.
2. Cleaning The Metals
The metals surfaces need to be free of grease, rust, oil, or dirt to ensure a decent connection between the metals. The metals need cleaning from these contaminants, which will form a barrier preventing proper connection.
The removal of oil and grease is the first step of cleaning. The solution for removing rust from the base metals will not perform if the metal has an oily or greasy surface. Dipping the metal in a degreasing solvent or using vapor degreasing removes the presence of any oil or grease from the surface of the metal.
3. Fluxing Of Parts
Oxidation reaction occurs when the heating metal in the presence of air. The oxidation process can inhibit the bonding of metals and brazing agent. You need to give a flux coating on the metal before heating to inhibit the oxidation process.
4. Assembling For Brazing
After cleaning and fluxing, you need to position the metals in the correct place before starting the brazing process. The metals need to be in alignment during both the heating and cooling processes to guarantee a good connection.
5. Brazing Process
You need to heat the brazing rod as well as the assembly of metals to the melting point of the filler material. A handheld torch is useful for quickly heating the metals and the brazing rod. Introduce a brazing rod to the joint area of the assembly after heating.
6. Cleaning After Brazing
After finishing the brazing process, the cleaning of the joint is mandatory as most fluxes are corrosive. The cleaning process consists of two steps -
- Removal of flux residues.
- Removing scales forming due to the oxidation process during brazing.
The lower thermal coefficient of cold spray is beneficial for some processes. The administration of the process is through acceleration and bombardment of the coating material.
The material causes local heating in the impact points and will bond with the surface. A thicker layer of coating is obtainable by repeating the process. The coating material is in the solid-state during administration.
The defects of conventional thermal spraying such as thermal stress, phase transformation, and oxidation are not present in cold spray. The high-velocity impacts during cold spraying create plastic deformation of the metal at impact zones.
Cold spray is a viable coating technique for alloys, pure metals, and even composites. Even though the cold spray is considerably cheaper than conventional spraying techniques, they have distinct advantages over its counterparts. Cold spraying is also beneficial to many welding processes such as electron welding.
Brazing vs Soldering
What is the difference between brazing and soldering?
The basic difference between soldering and brazing is the temperature which is necessary to melt the filler metal. Soldering is a low-temperature analog to brazing. Soldering takes place with fillers that melt at below 840°F (450°C). Metals that can be soldered include gold, silver, copper, brass, and iron. If the filler metal melts below 840ºF the process being performed is soldering.
YouTube Video | Field Brazing Tips & Techniques
In brazing, the metals which require joining do not need direct contact with flame. Instead, you must heat the brazing rods to it’s melting point and use this molten metal to fuse the metal pieces.
The cold spray has many advantages over the normal thermal spray process. The cold spray makes coating with nanostructure, which has considerable advantages in comparison to conventional coatings not using nanostructure.