The excellent strength-to-weight ratio, corrosion resistance, and durability of composite materials make them popular in a wide range of applications. However, due to their anisotropic, heterogeneous, and abrasive properties, machining composite materials is difficult. To manufacture high-quality components with precise dimensions and a smooth surface, composite materials call for specialised machining methods, cutting tools, and machining settings. This chapter will cover various composite machining techniques, cutting equipment, machining parameters, and difficulties encountered when performing composite machining.
There are three main methods used for machining composite materials are as follows.
Conventional Machining:
For machining composite materials, traditional techniques like milling, drilling, and turning are frequently utilised. However, due to their anisotropy, composite materials can be difficult to machine using traditional techniques. Delamination and fibre pullout result from the cutting forces changing depending on the direction of the fibres. Different cutting tool shapes, machining settings, and machining techniques have been developed to address these issues.
Abrasive Machining:
Finishing composite materials is frequently done using abrasive machining techniques like grinding and polishing. Compared to traditional machining, abrasive machining may produce parts with excellent precision and surface polish. However, the procedure takes a long time, and tool wear is rapid.
Non-Traditional Machining:
Composite materials are machined using unconventional techniques such as ultrasonic machining, water jet cutting, and laser cutting. Non-traditional machining techniques remove material from the workpiece using energy sources other than mechanical cutting. These techniques can produce excellent precision and surface finish while overcoming the difficulties associated with traditional machining. Contrary to traditional machining, the technique is more time- and money-consuming.
The need for composite materials is rising quickly across several industries, and composite machining is turning into a critical step in the creation of components of the highest calibre. However, the difficulties encountered during composite machining necessitate ongoing research and development to enhance the effectiveness and precision of the procedure.
Machining of Composite Materials
The following are some of the future directions in composite machining:
Development of Advanced Cutting Tools:
The creation of cutting tools with sophisticated technologies, such as nanocrystalline diamonds, CVD diamonds, and DLC-coated tools, can increase machining productivity and lessen tool wear. These more sophisticated cutting tools are harder and more resistant to wear, enabling faster cutting and longer tool life.
Optimization of Machining Parameters:
The efficiency of the machining process can be increased, and the danger of delamination, fibre pullout, and tool wear can be decreased, by optimising machining parameters including cutting speed, feed rate, cutting depth, and coolant/lubrication. The optimization of machining parameters might benefit from the use of simulation techniques, such as finite element analysis (FEA).
Development of Monitoring and Control Systems:
Real-time feedback on the performance of the machining process can be obtained through the construction of monitoring and control systems. Some examples of these systems are acoustic emission monitoring, force monitoring, and temperature monitoring. These systems can detect and avoid delamination, fibre pullout, and tool wear, which contributes to an increase in both efficiency and accuracy during the process.
Integration of Composite Machining with Additive Manufacturing:
It may be possible to create complicated composite structures with greater accuracy and efficiency by combining composite machining with additive manufacturing, such as 3D printing. Combining these two procedures can increase design freedom, decrease waste, and bring down the price of making composite parts.
Smart Machining:
Artificial intelligence (AI) and machine learning (ML) techniques are included in the machining process as part of smart machining. With real-time parameter optimization and anomaly detection provided by smart machining, efficiency, accuracy, and quality may all be improved.
Multifunctional Machining:
In multifunctional machining, different machining operations including cutting, drilling, and milling are combined into a single machine configuration. By reducing the number of setups needed, multifunctional machining can shorten lead times, boost productivity, and cut costs.
Hybrid Machining:
In hybrid machining, various machining processes—including laser machining, water jet machining, and electrical discharge machining (EDM)—are combined with more conventional machining processes. New options for creating complicated components with great accuracy and efficiency may be provided by hybrid machining.
Sustainable Machining:
The environmental impact of composite machining can be further diminished by using sustainable machining methods like circular machining and green machining. Utilizing renewable energy sources to run the machining process, such as solar and wind power, is known as green machining. Machine scrap and byproducts are reused and recycled during circular machining.
Smart Factory:
The combination of composite machining with ideas from the smart factory, like Industry 4.0, may present new chances to raise the effectiveness, precision, and calibre of the procedure. Real-time monitoring and management of the machining process are possible with the help of smart factory concepts, which can lead to increased productivity, shorter lead times, and lower costs.
Written by:
Dr. Atul Babbar
Assistant Professor
Mechanical Engineering Department
SGT University
