1. Consider the structure of the workpiece
When designing the structure of the workpiece, not only the use performance of the workpiece should be considered, but also the adaptability of this structure to the processing process. The processing methods corresponding to different workpiece structures are different, in order to ensure the processing of thin-walled parts. The accuracy of the workpiece structure is particularly important. Generally speaking, the application of thin-walled parts processed from titanium alloy plates has higher accuracy requirements and usage requirements. The deformation of the parts will not only cause difficulties in the process of installation, but also may not be able to complete the design parts. What needs to be done. Therefore, in order to avoid deformation of the workpiece during processing, first, consider designing the workpiece into a symmetrical structure. This structure enables the release of internal forces of each part of the workpiece during processing to be synchronized to avoid internal force distribution. Unequal conditions. Second, in the design of the thin plate, try to ensure that the thickness of the entire thin plate is as consistent as possible, and at some corners of the workpiece, due to processing or heat treatment, stress concentration may occur. The transition can be made by designing the corner to a circular arc structure. , Thereby reducing the deformation of the workpiece.
2. Consider from the perspective of workpiece clamping
The thin-walled parts themselves are thinner and only have lower stiffness, that is to say, the ability of the workpiece to resist elastic deformation is weak. Therefore, during the processing of the workpiece, the clamping will also affect the workpiece to a large extent. Deformed. The clamping is mainly used to fix the workpiece, and the clamping is used to locate the workpiece and ensure the stability of the workpiece during processing, as shown in Figure 3. Unreasonable clamping position and clamping force will cause the machining accuracy to decrease. Therefore, when selecting the clamping position, try to ensure that the clamping positions are in a symmetrical relationship, and the clamping force can be adjusted according to the rigidity of the workpiece. When the rigidity of the workpiece is high, a larger clamping force can be selected, but special attention should be paid to the fact that when the rigidity of the workpiece is low, an appropriate clamping force must be selected, otherwise it is easy to cause deformation of the workpiece during processing.
3. Consider from heat treatment
The general heat treatment of the workpiece is completed by quenching and artificial aging treatment, and the timing of the heat treatment of the workpiece is very important to reduce the deformation of the workpiece. Because when the workpiece is heat treated, the temperature stress and phase change stress will be generated inside the workpiece due to the change of the workpiece's own temperature, which is the main reason for the deformation of the workpiece. At the same time, heat treatment can not destroy the mechanical properties of the workpiece, so it is generally considered to arrange the timing of the heat treatment before the rough machining of the blank. Therefore, the timing of heat treatment should be rationalized as much as possible, so as to ensure the mechanical properties of the workpiece and reduce the deformation caused by the heat treatment of the workpiece.
4. Consider from the process method and cutting fluid
In the process arrangement of workpiece processing, firstly, according to the different composition and structure of different types of workpieces, the process arrangement should be carried out. Among them, special attention should be paid to the analysis of the easily deformed parts of the workpiece during processing, and whether Reduce the amount of deformation of the workpiece through some adjustments in the process. Secondly, when roughing the workpiece, it is necessary to reserve a large cutting margin at the beginning, and do a good job of positioning the reference surface. As the workpiece is processed, it is necessary to always pay attention to the correction of the reference surface, because the processing The reduction of the margin in the process will inevitably bring about a change in the reference level. The choice of cutting fluid is mainly based on the nature of processing and processing tools. The reasonable use of cutting fluid according to different process arrangements and tool usage will help improve the efficiency of workpiece processing.
5. Elimination of residual stress of thin-walled parts
The initial residual stress of thin-walled parts is generally determined by the heating factors of the blank material, and the processing residual stress is generally reflected after the processing of the thin-walled parts, so the research on the residual stress is worth paying attention to, how to predict The influence of residual stress and how to eliminate the influence of residual stress on the processing quality of parts.
Although the source of the residual stress in thin-walled parts is known, its influence on the deformation of thin-walled parts in processing can not be accurately determined, because the residual stress of thin-walled parts leads to deformation of thin-walled parts, which are generally caused by heating factors and mechanical forces. The result of the effect. At present, the control of residual stress generally uses the current more popular finite element analysis method to establish a finite element model of thin-walled parts and uses numerical analysis to predict the impact of residual stress. In addition, this method can not only simulate the results of deformation correction of thin-walled parts but also predict springback.
At present, the methods to eliminate residual stress of workpiece blanks include pre-stretching, vibration aging, aging annealing and cryogenic treatment. Among these methods, the cryogenic treatment application is the most successful. Cryogenic treatment can effectively reduce the residual stress in thin-walled parts. At the same time, the treatment can also increase the hardness and strength of the parts, improve the wear resistance of the workpiece, and increase the service life of the parts. In addition, cryogenic treatment can ensure the dimensional accuracy of the parts and improve the internal stress distribution in the parts. To reduce the impact of machining residual stress on the deformation of parts, it is still necessary to start from the aspect of reducing cutting heat.
titanium rod Medical Grade Titanium Wire titanium welded tubing titanium rolling plate
titanium rod Medical Grade Titanium Wire titanium welded tubing titanium rolling plate
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