β21s高强度钛合金的铣削试验研究

针对一种新型的难加工钛合金材料β21s,进行了刀具磨损试验和铣削力的测量试验,对材料的切削加工性进行评价,并且给出优选结果,为实际生产提供参考。     

铝合金薄板尖边缘缺口试样的机械加工方法及缺口敏感性测试

介绍高强度铝合金薄板的尖边缘缺口拉伸试样的机械加工方法，用该方法制备的仿美７０７５、美制７０７５、国产ＬＣ４、ＬＣ９、ＬＹ１２、ＬＢ７３３等６种铝合金１６种热处理状态下的ＥＮ试样，其内率半径Ｒ满足了ＡＳＴＭＥ３３８－６８标准方法中Ｒｍａｘ０．０１８毫米的要求，并且达到Ｒ＜０．０１０毫米的特高精度。同时，还对仿美７０７５、美制７０７５、国产ＬＣ４的６种热处理状态下的缺口敏感性和宏观断口、以及选择仿美７０７５、ＬＹ１２对扫描断口形态进行了研究。     

Machining with tool–chip contact on the tool secondary rake face—Part II: analysis and discussion

The forces, chip thickness, and natural tool–chip contact length in machining with a double-rake-angled tool are predicted in Part II of the present study. It is revealed that in comparison with a single-rake-angled tool, a double-rake-angled tool increases the forces, especially the thrust force. However, the increase in chip thickness and tool–chip contact length is not significant under the input conditions specified in the present study. The effect of seven input variables of the proposed model is quantitatively investigated. The predicted variations of forces, chip thickness, and natural tool–chip contact length are in good agreement with theoretical and experimental results obtained by other researchers. The interrelationships among the resultant force, the chip thickness, and the natural tool–chip contact length are established, which provides a new and promising method to estimate the tool–chip contact length by employing the resultant force. It is demonstrated that the model can also be extended to study the problem of machining with a groove-type chip breaker tool.     

Computerised trace method for establishing equations for dimensions and tolerances in design and manufacture

A computerised trace method has been developed for determining the relationships of assembly requirements with design dimensions and tolerances of the components in an assembly, and the relationships of design specifications and machining allowance requirements with manufactured dimensions and tolerances of the component in a process plan. This method traces from the proposed components or planned operations only the dimensions and tolerances that affect the given requirement, and therefore the equations for design or for manufacture can be established simultaneously and accurately. Hence it is possible to establish constraints for the optimisation of dimensions and tolerances for design or for manufacture.     

Diffusion Bonded EDM Electrode with Micro Holes for Jetting Dielectric Liquid

This paper describes improvement of machining characteristics of electrical discharge machining of deep slots using a tool electrode which has micro holes for jetting dielectric liquid over the working surface. The tool electrode was made by the diffusion bonding of two copper plates, over an interface on which micro grooves for jetting the dielectric fluid were formed using electrolyte jet machining. In conventional machining, it is difficult to drill micro holes at the end of a slim electrode and circulate the dielectric fluid from the other end. Hence a solid tool electrode is used and periodically lifted up during machining to flush debris particles out of the discharge gap. Use of the newly developed tool electrode was found to shorten the processing time and improve machining accuracy significantly compared with the conventional solid tool electrode. Since the holes are micro, the outlet shapes are not replicated onto the bottom surface of the slot machined.     

主轴回转误差对加工影响的数学描述

就车床、镗床类机床主轴纯径向跳动和终了角度摆动所产生的加工误差进行了单因素分析，并给出了较为精确的数学表达。     

Digital twin modeling method based on biomimicry for machining aerospace components

High-performance aerospace component manufacturing requires stringent in-process geometrical and performance-based quality control. Real-time observation, understanding and control of machining processes are integral to optimizing the machining strategies of aerospace component manufacturing. Digital Twin can be used to model, monitor and control the machining process by fusing multi-dimensional in-context machining process data, such as changes in geometry, material properties and machining parameters. However, there is a lack of systematic and efficient Digital Twin modeling method that can adaptively develop high-fidelity multi-scale and multi-dimensional Digital Twins of machining processes. Aiming at addressing this challenge, we proposed a Digital Twin modeling method based on biomimicry principles that can adaptively construct a multi-physics digital twin of the machining process. With this approach, we developed multiple Digital Twin sub-models, e.g., geometry model, behavior model and process model. These Digital Twin sub-models can interact with each other and compose an integrated true representation of the physical machining process. To demonstrate the effectiveness of the proposed biomimicry-based Digital Twin modeling method, we tested the method in monitoring and controlling the machining process of an air rudder.     

Physics-guided logistic classification for tool life modeling and process parameter optimization in machining

This paper describes a physics-guided logistic classification method for tool life modeling and process parameter optimization in machining. Tool life is modeled using a classification method since the exact tool life cannot be measured in a typical production environment where tool wear can only be directly measured when the tool is replaced. In this study, laboratory tool wear experiments are used to simulate tool wear data normally collected during part production. Two states are defined: tool not worn (class 0) and tool worn (class 1). The non-linear reduction in tool life with cutting speed is modeled by applying a logarithmic transformation to the inputs for the logistic classification model. A method for interpretability of the logistic model coefficients is provided by comparison with the empirical Taylor tool life model. The method is validated using tool wear experiments for milling. Results show that the physics-guided logistic classification method can predict tool life using limited datasets. A method for pre-process optimization of machining parameters using a probabilistic machining cost model is presented. The proposed method offers a robust and practical approach to tool life modeling and process parameter optimization in a production environment.