Conventional vs. Non-Conventional Machining: Key Differences Explained

Whether the input form of the material is bar stock, a forging or casting, precision machining process is employed to produce accurate components with tight tolerances and excellent surface quality. Material is removed from the workpiece during machining to achieve the desired end results. Precision machining often involves the use of computer numerical controls, or CNC, which enables the conversion of special designs into exact shapes through multiple dimensions.

Conventional machining processes involve the direct contact of tools and workpieces. Unconventional machining processes do not require the direct contact of tool and workpiece. This article looks at the differences between conventional and non-conventional machining processes.

What are Conventional Machining Processes?

Conventional machining processes rely on harder tools or abrasive materials to remove material from the workpiece. This is typically achieved using metal tools that cut or grind away material from the workpiece to create a desired shape. Conventional machining includes processes such as milling, boring, slotting, deburring, grinding, and drilling, which are controlled by computer software.

What are Non-Conventional Machining Processes?

As opposed to the direct contact of conventional machining, non-conventional machining processes utilize other forms of energy such as electrical, thermal, and chemical to remove unneeded material. They are ideal to process tough or brittle materials with complex geometries. Examples of non-conventional machining processes include:

• Electrical Discharge Machining (EDM): A widely-used machining process, this technique creates a series of isolated electrical sparks created between the workpiece and the electrode to remove unwanted material. This process can only be used with electrically conductive materials.
• Chemical Machining (CM): This is the controlled dissolution of workpiece material using a strong chemical reagent. The material is removed from selected areas by immersing the workpiece in a chemical reagent such as an acid or alkaline solution.
• Electrochemical Machining (ECM): This metal-removal process is based on the principle of reverse electroplating. Here, a current of electrolyte fluid carries particles away from the workpiece toward the machining tool.
• Laser Beam Machining (LBM): LBM is a thermal material-removal process that utilizes high-energy light beams to melt and vaporize particles on workpiece surfaces. Its high degree of accuracy is appropriate for cutting, drilling, and welding.
• Ultrasonic Machining (USM): This material removal process uses high-frequency mechanical motion and an abrasive slurry to create intricate workpiece profiles.
• Water Jet Cutting (WJC): It is an erosive process that uses high-pressure water to cut through materials to achieve desired shapes. No heat is applied to the materials during the water jet cutting process.
• Abrasive Water-Jet Cutting (AWJC): In this version of water jet cutting, abrasive particles added to the water jet increase the material removal rate. This machining process is ideal for cutting heat-sensitive materials that cannot be cut by laser or thermal processes.

 What are the Differences Between Conventional and Non-Conventional Machining Processes?

Although both eventually accomplish the same end purpose, there are certain differences to be noted between conventional and non-conventional machining processes:

• Materials: Non-conventional machining methods are often used to process difficult-to-machine materials such as superalloys as easy tool worn-out and high tool consumption will render conventional machining very expensive and less efficient.
• Cost: While conventional machining generally costs less, non-conventional machining methods such as electrochemical machining and waterjet cutting can simultaneously process multiple workpieces to achieve great productivity thereby reducing unit costs. Parts produced by nonconventional machining methods usually require less to no post-processing finishing operations.
• Complex geometry: Nonconventional cutting can work with workpieces of complex geometries in hard metal, which cannot be accomplished by conventional machining without expensive tooling, fixture, or high tool consumption.
• Mechanical stress: Many nonconventional machining processes such as chemical machining, and water jet cutting do not undergo thermal or mechanical stress, which is beneficial for a work surface used for sealing purposes.
• Volume: Non-conventional machining processes such as waterjet cutting are designed for high-volume production at a lower cost.

 Learn More About the Differences Between Conventional and Non-Conventional Machining Processes

Impro is a global, integrated manufacturer of high-precision, high-complexity and mission-critical components for diversified markets. We use state-of-the-art process technologies and equipment throughout our manufacturing operations. If you are interested in finding more information about our precision machining capabilities, conventional or non-conventional, please contact our team of experts today.