What do I need to be aware of when machining speciality materials?

Special materials processing due to the uniqueness of its material properties, in the process of processing needs to be extra cautious, from a number of aspects to pay attention to, in order to ensure the processing quality and safety.

First, accurately grasp the characteristics of the material

Special materials have their own special physical and chemical properties. For example, ceramic matrix composites are extremely hard and brittle, which requires processing to avoid the use of high-impact processes to prevent the material from cracking. When cutting such materials, it is appropriate to use laser cutting and other non-contact processing methods, the use of laser's high energy density to achieve fine cutting, reducing the damage to the material.

Part of the metal-based speciality materials, such as titanium alloys, chemical properties of active, easy to chemical reaction with some components of the cutting fluid in the processing. Therefore, it is necessary to choose the cutting fluid to match, to prevent chemical reactions lead to changes in material properties.

Second, a reasonable choice of processing technology

1. cutting: cutting special materials, cutting tool selection is critical. In the face of high hardness of special materials, such as cemented carbide, ordinary tools are difficult to cope with the need to use cubic boron nitride tool, which has a very high hardness and wear resistance, can effectively reduce tool wear, to ensure machining accuracy. At the same time, cutting parameters such as cutting speed, feed and depth of cut need to be precisely adjusted according to the material characteristics. Usually for difficult to process special materials, cutting speed should not be too fast, in order to prevent changes in material properties due to high temperature.

2. Speciality machining: EDM is commonly used for electrically conductive speciality materials. During the machining process, the discharge parameters should be precisely controlled. Excessive discharge current will produce too deep a discharge pit on the material surface, affecting the surface quality; improper discharge frequency may lead to low processing efficiency. When laser processing, the laser power, spot size and other parameters should be adjusted according to the material's absorption rate of the laser. Like the high reflectivity of metal materials for laser perforation, you need to increase the laser power to ensure that the material can fully absorb the energy to achieve the purpose of perforation.

Third, strict control of quality testing

1. Processing accuracy testing: special materials processing requires high precision. After processing is completed, it is necessary to use high-precision measuring instruments, such as CMM, to test the dimensional accuracy of the parts. For the complex shape of the special material parts, such as aerospace engine blades, but also the use of optical scanning technology, the shape of the accuracy of a full range of testing to ensure that with the design requirements.

2. Surface quality detection: surface roughness is an important factor affecting the performance of special materials. Through the surface roughness instrument detection, if the surface roughness does not meet the requirements, it may affect the wear resistance and corrosion resistance of the parts. In addition, it is also necessary to use non-destructive testing techniques, such as ultrasonic flaw detector, to check the surface of the material and the interior of the cracks and other defects to ensure the integrity of the material.

 Fourth, strengthen the awareness of safety and environmental protection

1. Safe operation: special materials processing equipment often has a high degree of risk. Operators must be rigorously trained and familiar with the operating procedures and emergency braking measures of the equipment. For example, when operating laser processing equipment, wear specialised protective eyewear to prevent laser damage to the eyes.

2. Environmental protection treatment: Wastes generated during processing, such as cutting fluids containing heavy metals and edge wastes of special materials, must be properly treated. Adopt special waste liquid treatment equipment to purify the cutting fluid and achieve resource recycling; classify and collect the waste materials and hand them over to professional institutions for harmless treatment to avoid pollution to the environment.

Special materials processing is a complex and delicate work, only in the processing of comprehensive attention to the above aspects, in order to achieve high-quality processing, to promote the wide application of special materials in various fields.