Composite parts vs steel parts
The benefits of using composite parts compared to metals are numerous. From their superior performance in harsh environments to their ability to be moulded into complex shapes, composite parts offer durability, a strength-to-weight ratio, and structural properties not possible in steel parts. Here, we outline where, when, and why you may find composite parts vs steel parts may be more beneficial to your business’ needs.
Where to use composites?
One of the key advantages of composite materials is their superior performance in harsh environments, particularly when compared to traditional steel parts.
In high-salinity environments, such as coastal areas or salt mines, traditional steel parts can quickly corrode and deteriorate, resulting in costly repairs and the need for regular replacement. Instead, composite parts are highly resistant to corrosion and can withstand exposure to saltwater and other corrosive substances for extended periods of time. This makes composites an ideal choice for marine applications, such as boat hulls, in the mining industry and in underwater environments.
In tropical or subtropical climates or other locations with high humidity, steel parts can also suffer from corrosion and rust. The parts can also be surface finished, with for example graffiti or UV-resistant paint in any colour to match aesthetics or branding, or finished in Safety Yellow to meet safety requirements.
For underground applications, such as in mining or tunnelling, composite parts offer several important advantages over steel. Because composite componentry is lightweight and can be easily moulded into complex shapes, they can be used to create parts that are both strong and durable, while also being lightweight and easy to handle. More often than not in projects with large-scale equipment, steel components become a safety issue for the users and maintenance staff. By reducing the weight, composite parts can increase the safety of the people, reduce the wear and tear on equipment (and thereby costs), and reduce time and cost savings on maintenance outlay, by making the parts easier to carry or move if needed and reducing maintenance overall. Composite Components have helped many clients determine whether the cost outlay of new moulds and composite parts will have a positive financial return on their investment when considering cost savings by switching to composites such as fuel etc...
Why use composites and carbon fibre?
As you likely are aware, Carbon fibre is used extensively in Formula 1 racing. This is because of its superior strength-to-weight ratio, stiffness, and durability. These properties make carbon fibre an ideal material for creating lightweight, high-performance components to withstand the extreme forces and stress experienced during an F1 race, in flight or in structures subject to high loads.
This strength-to-weight ratio is often viewed as the largest advantage of carbon fibre. Carbon fibre is five times lighter than steel for the same strength and 3.8 times the tensile strength of aluminium. This means that components made from carbon fibre can be much lighter than their metal counterparts, while still maintaining the necessary strength and stiffness to perform effectively in a variety of applications. This reduction in weight can help to improve the performance and handling of products.
In addition to its strength-to-weight ratio, carbon fibre is also highly resistant to fatigue. This is important, particularly in the mining industry, where components are subjected to repeated loading and unloading. Carbon fibre’s ability to resist fatigue means that components made from this material can withstand the rigours of use over time, without requiring frequent replacement or repair.
Carbon fibre can bend but will not conform to a new shape. Once the tensile strength of carbon fibre is exceeded though, the carbon fibre can suddenly fail, meaning that the engineering is critical in ensuring a part will last. Composite Components find that using Finite Element Analysis (FEA) and Computational Fluid Dynamics (CFD) is a crucial process in designing parts for structural analysis and solving fluid dynamics problems.
Carbon fibre and composite constructions are also highly customizable, allowing engineers to design components with specific performance characteristics in mind. For example, the orientation and number of carbon fibre plies used in a component can be tailored to provide specific levels of stiffness, strength, or impact resistance. This level of customization allows optimization of the performance of various products and can give companies an edge over the competition.
Composite materials may also offer environmental benefits when compared to traditional steel parts. Because composite parts are lighter and more durable than steel, they can help reduce fuel consumption and greenhouse gas emissions in transportation applications.
How does Composite Components make their parts?
At Composite Components, we use a various of methods for manufacturing parts. We are not limited to any specific process, but our specialization is in producing high-quality composite parts using a material known as prepreg. This involves impregnating cloths made of carbon fibre or other reinforcing fibres, such as glass fibre, or Kevlar with a thermoset resin matrix. The resin matrix is typically a two-part epoxy that is designed to cure when exposed to heat and pressure, creating a strong and durable bond between the fibres.
But in order to get to that final prepreg part, the first stage in the process is to create a mould or tooling that is designed to the exact specifications of the finished part. This can be done using a variety of materials, such as fiberglass or metal, and often through of computer-aided design (CAD) software to ensure accuracy. Here at Composite Components, we use a sophisticated program called Rhino and use our CAM software to ‘talk’ to our machines and program the cutting of accurate moulds.
Once the mould is complete, the next step is to lay down a layer/s of prepreg cloth and/or foam core to create a solid carbon part or a sandwiched core or composite part. The foam is typically a closed-cell foam that is chosen for its light weight and high strength-to-weight ratio. The foam core helps to maintain the shape and structural integrity of the part.
The carbon fibre layers are typically laid down in a specific sequence, with each layer being carefully positioned and oriented to ensure optimal strength and stiffness in the finished part. The number and orientation of the carbon fibre layers can be customized to meet the specific requirements of the part, such as load-bearing capacity or resistance to environmental factors like heat or moisture.
Once all of the layers have been laid down, the next step is to apply pressure and heat to the part. This is typically done using a vacuum bagging process, where the part is wrapped and sealed within an airtight bag and vacuum pressure is applied by a vacuum pump. The vacuum is used to remove any air from the bag, creating a tight seal around the part and atmospheric pressure (14.5psi at sea level) applies the pressure required to consolidate the layers within. Heat is then applied to cure the resin matrix. Alternatively, we use a heated press that achieves a similar outcome but is a shorter timeframe and with additional pressure, the better the pressure, the better the part. The process chosen will depend on many factors, the mould type, part size, quantity required, timeframe and application. Both curing processes ensure that we create parts that minimise air pockets (voids) or excess resin, to ensure the strongest possible bond.
Finally, once the part has cured, it is removed from the mould and any excess material is trimmed away. The part may be left as is, with the surface finish being defined by the surface of the mould, or the part may be finished to the client’s needs for example painted in our spray booth, or finished with other coatings.
Overall, the process of building composite parts with prepreg carbon fibre and foam cores is complex and requires a high level of skill and expertise. However, the superior outcome of composite parts compared to steel or aluminium makes it an ideal choice for a wide range of applications, from aerospace and defence to mining, medical, and marine.
If you're looking for a reliable, high-quality composite manufacturer in Australia, have a chat with us at Composite Components. As a leader in the composites manufacturing industry, Composite Components is dedicated to providing high-quality carbon fibre and composite parts to a variety of industries.