1 Scope
This document specifies the classification of laser surface cleaning, general requirements, process preparation, cleaning procedures and quality control requirements.
This document applies to the workpiece surface metal oxides, coatings, coatings and other specific contaminants of laser cleaning, including pre-welding, pre-assembly, cleaning of contaminants before the preparation of coatings, post-welding, post-processing surface contaminant removal and functional (protection, modification, etc.) failure of the surface material removal.
2 Normative references
The contents of the following documents constitute essential provisions of this document by means of normative references in the text. Where a reference is dated, only the version corresponding to that date applies to this document; where a reference is not dated, the latest version (including all amendments) applies to this document.
GB/T 228.1 Metallic Materials Tensile Testing Part 1: Test Method at Room Temperature
GB/T 232 Metallic Materials Bending Test Method
GB/T 1031 Geometrical Product Specifications (GPS) - Surface texture - Profile method - Surface roughness parameters and their values
GB2894 Safety Signs and Guidelines for Use
GB/T 3138 Terminology for Treatment of Metallic and Other Inorganic Coatings
GB/T 3354 Test Method for Tensile Properties of Oriented Fiber Reinforced Polymer Matrix Composites
GB/T 3356 Test Method for Flexural Properties of Directional Fiber Reinforced Polymer Matrix Composites
GB/T 4340.1 Metallic Materials Vickers Hardness Test Part 1: Test Method
GB/T 5226.1 Safety of Machinery Electrical Equipment of Machinery Part 1: General Technical Conditions
GB/T 5270 Metallic Coatings on Metallic Substrates - Review of Test Methods for Adhesion Strength of Electrodeposited and Electrodeposited Coatings
GB 7247.1-2012 Safety of Laser Products Part 1: Equipment Classification, Requirements
GB/T 7247.14 Safety of Laser Products Part 14: User's Guide
GB/T 15,313 Laser Terminology
GB/T18490.1 Safety of Machinery - Laser Processing Machines - Part 1: General Safety Requirements
GB/T 18490.2 Safety of Machinery - Laser Processing Machines - Part 2: Safety Requirements for Handheld Laser Processing Machines
GB/T 18683 Laser Surface Hardening of Iron and Steel Parts
GB/T 28786 Vacuum Technology - Measurement of Adhesion Strength of Vacuum Coatings - Tape Bonding Method
GB/T 30707 Test Method for Adhesion of Fine Ceramic Coatings Scratch Method
GB/T 33049 Test Method for Adhesion of Optical Film Coatings for Polarizers
3 Terms and definitions
The terms defined in GB/T 3138, GB/T 18683, GB/T 15313 and the following terms and definitions are applicable to this document.
3.1
Laser surface cleaning
The process of using a laser beam to remove contaminants and unwanted materials from the surface of a workpiece.
Note: abbreviated as "laser cleaning".
4 Cleaning classification
Laser cleaning according to the type of removal can be divided into three categories:
a) Ⅰ: metal oxides and coatings, including electrochemical / chemical oxide film, rust and oxides, coatings, inorganic films, etc.;
b) Class II: coatings, including wave absorbing coatings, thermal control coatings, lubricating coatings, organic coatings, etc;
c) Category III: specific contaminants, degraded material surfaces or residues, including oil, degraded surfaces, carbon deposits, solder stoppers, adhesive layers, fouling, etc.
5 General requirements
5.1 Operators
Laser cleaning operators should be engaged in the relevant processes, equipment operation and safety training, after passing the assessment before they are allowed to work.
5.2 Operating environment
5.2.1 Laser cleaning operation environment should be kept clean and ventilated, the ambient temperature should be within 5 ℃ ~ 30 ℃, the relative humidity should not be greater than 75%.
5.2.2 laser cleaning site should be in accordance with the provisions of GB 2894 with obvious safety signs, and set up fences, partition walls, screens, etc., to prevent people not related to the work from entering the danger zone.
5.2.3 Laser cleaning site should not have flammable and explosive materials. Should not be in a specific environment where open fire is prohibited for laser cleaning.
5.3 Working voltage
The supply voltage should be AC 220 V, 50 Hz or AC 380 V, 50 Hz, and should be kept stable.
5.4 Cleaning equipment
5.4.1 The laser cleaning equipment should contain the laser, scanning actuator, control system, cooling device and laser safety protection device.
5.4.2 Laser cleaning equipment should ensure the uniformity of the cleaned surface and should not show edge ablation and steps.
5.4.3 laser cleaning equipment optical system should be closed or take protective measures (such as making the laser in the metal tube to pass) to avoid direct illumination
The human body is harmed by direct light.
5.4.4 Laser cleaning equipment should be shielded by protective devices such as laser shielding glass to prevent the reflection of laser light.
5.4.5 The radiation safety of laser cleaning equipment should comply with the requirements of GB 7247.1-2012, Chapter 4, and should be marked in accordance with the requirements of GB 7247.1-2012, Chapter 5, on laser radiation safety.
5.4.6 Other safety protection should be in accordance with GB/T 5226.1, GB/T 7247.14, GB 2894, GB/T 18490.1, GB/T 18490.2 of the provisions of the implementation.
6 Process preparation
6.1 Process preparation content
Process preparation may include process program development, process protocol preparation, process test
7 Cleaning process
7.2.1 cleaning process should be based on the process documentation, according to the workpiece's own characteristics, reference to existing experimental data, to determine the range of process parameters, through the verification of the cleaning process parameters.
7.2.2 cleaning should be followed from the near end to the far end or from the upper end of the workpiece to the lower end of the principle of gradual cleaning.
7.2.3 cleaning thin-walled workpiece and mesh workpiece, cleaning power should be controlled, it is appropriate to use low power multiple cleaning to avoid deformation of the workpiece. 7.2.4 workpiece oil is thick, the oil can be pretreated to reduce the thickness of the oil, and adjust the cleaning power to avoid open fire.
7.2.5 cleaning dirt or coating thickness is not uniform workpiece, should be used to clean the principle of low power multiple cleaning, or dirt, coating thicker areas for separate cleaning.
7.2.6 for flammable dirt, coating or easy to oxidize the material laser cleaning, as well as the cleaning of the surface has special application requirements of the workpiece, in the laser cleaning process should be used to protect the inert gas.
7.2.7 The fumes and exhaust gases generated by cleaning should be removed or collected by means of side blowing airflow or vacuuming.
7.3 Workpiece protection
7.3.1 The workpieces that have passed the cleaning inspection should be protected according to the different materials and surface states.
7.3.2 Protection media and protection methods should be selected according to the different turnover, transport and storage cycles.
7.3.3 During the cleaning process, the surface of the workpiece should be protected from knocks.
7.3.4 After cleaning, the workpiece should be stored in a dry place.
8 Quality control
8.1 Basic requirements
Process personnel should be based on the cleaning of the workpiece batch (such as a small batch in a batch or a large number), the degree of importance (such as important pieces, key pieces or key processes) or the user's special requirements for effective control of cleaning quality, the development of the corresponding quality control documents, clear test items and test requirements.
8.2 Process assessment
8.2.1 Assessment conditions and requirements
8.2.1.1 When the following circumstances occur, the process should be assessed:
a) When a new process is adopted for the first time;
b) when major production equipment has been changed or overhauled;
c) when major process conditions change, including base materials, removals, etc.; d) when required by the user.
8.2.1.2 Process evaluation items and requirements shall be carried out in accordance with Table 1. If the user has special requirements, the optional items may be used as mandatory items.
8.3 Inspection methods
8.3.1 General requirements
According to the cleaning requirements of the workpiece, the surface of the workpiece after laser cleaning shall be inspected routinely. The inspection items shall include appearance, surface roughness, coating adhesion, etc. The test results and test methods shall be in accordance with the requirements of 8.3.2 to 8.3.4.
8.3.2 Appearance
Observation with the naked eye or magnifying glass, the surface of the workpiece after laser cleaning should not be obvious dirt or residual removal, there should be no new cracks, scars and etching pits and other defects. When the user has cleanliness requirements for the workpiece, the cleanliness inspection is carried out in accordance with user requirements.
8.3.3 Surface roughness
According to the provisions of GB/T 1031 to assess the surface roughness of the laser cleaned workpiece. When laser cleaning is the pre-coating process, the surface roughness inspection after cleaning should be carried out according to the process requirements of the later process. When laser cleaning is the final process of the workpiece, the surface roughness level after laser cleaning should not change more than one level. Surface roughness can be determined using a probe type profile measuring instrument or a three-dimensional optical profile measuring instrument.
8.3.4 Coating bonding force
When the laser cleaning for spray layer removal and surface deposition layer removal, as well as other special requirements for the bonding of the coating removal, should be laser cleaning after re-preparation of the coating bonding force detection, laser cleaning of the substrate surface and re-preparation of the coating bonding force should not be lower than the coating removal before the bonding force, and in accordance with the following provisions.
Appendix A (informative) laser surface cleaning recommended process parameters
Bibliography
1 Scope
2 Normative references
3 Terms and definitions
4 Cleaning classification
5 General requirements
6 Process preparation
7 Cleaning process
8 Quality control
Appendix A (informative) laser surface cleaning recommended process parameters
Bibliography
