What does material assembly consist of?
Making an assembly consists of binding two materials together in order to create a mechanical bond. In this article we will detail different techniques of assembly.
What is an assembly?
All materials can be assembled, but the efficiency of the assembly will depend on several physico-chemical parameters. The choice of the assembly procedure must therefore conform to your specific needs and constraints.
These are the main considerations to bear in mind:
- What are the materials to be assembled? (Metal, plastic, composite, wood, glass, etc.)
- Will there be any treatments? (pickling, plasma, primer)
- How rough is the surface?
- What is its size, weight and density?
- What are the mechanical constraints? (static, dynamic, shear, traction, peel, cleavage)?
- What is the environment? (temperature, UV, humidity, presence of solvents, chemicals)
- What is the procedure for assembly?
An assembly can be:
- Permanent (non-removable)
- Indirect, through a 3rd material
The different assembly techniques
There are several methods of mechanical assembly; these are the most widely used:
Examples of indirect mechanical assemblies
Examples of direct mechanical assemblies
- Irreversible elastic binding between two pieces. A common assembly method in the plastics industry.
- Interference fit: assembly of two parts through reversible deformation, using controlled mechanical tolerances.
Mechanical assembly: disadvantages
Indirect methods of mechanical assembly have the disadvantage of causing mechanical stresses in the materials and are sometimes synonymous with deterioration (drilling, deformations, cracks, etc.)
Welding or brazing assembly
Welding and brazing are procedures that allow assembling materials through fusion. These highly technical procedures are commonly used for assembling metal structures.
Welding is an irreversible assembly method, particularly difficult to perform with metals. In fact, it can deteriorate mechanical properties if poorly controlled and usually requires post-treatment.
Metals are not the only materials involved in welding: thermoplastics are commonly assembled using this method, for example to seal plastic packaging.
Assembly through bonding
Bonding is a method that allows joining two materials using an adhesive mass.
Thanks to technical progress made by manufacturers, it is now possible to assemble practically any material through bonding, whether for structural applications or not.
Adhesive film assembly
An adhesive film is a thin material on which an adhesive mass is placed (glue). When this film is covered with adhesive on both sides, it can be used to join two materials permanently.
We can also perform removable assemblies, using:
- Double-sided Velcro® tape
- Adhesive magnetic tape
Advantages of adhesives and adhesive strips
Besides being versatile, assembly methods that use adhesives have the advantage of not modifying the core properties of materials, unlike welding and indirect mechanical assemblies.
Which type of assembly should you choose?
Any assembly is possible, as long as you choose the right procedure. Would you like to preserve the integrity of the materials to be assembled? If so, choose indirect assembly methods such as bonding or the use of adhesives.
Don’t hesitate to get in touch with an ADDEV Materials expert to learn more!