Zhen Jia Li

Analysis of Chip Breaking Prediction in Cutting Aluminum Alloys

As machining technology develops toward the unmanned and automated system, the prediction of chip breaking is considered increasingly important, especially in continuous machining such as in cutting aluminum alloys. In this paper, chip breakers with different parameters are designed to produce chips that can be evacuated easily and reliably from the working zone. The formulation of chip up-curl radius is constructed through analyzing the chips subject to chip breaker. The predictive model of chip breaking is developed based on chip breaking conditions. Chip breaking strain is obtained by using backward-deducing method and cutting experiments. In order to verify the model, PCD tools with chip breakers are used to cut LY12, chip breaking areas are compared with those obtained from the predictive model. Results show the chip breaking predictive model is reasonable.

Research on Heating Density Function and Temperature Field Mathematical Model for Milling Insert with 3D Complex Groove

Based on the milling temperature experiments and researches, we established the milling temperature mathematical model using dimension analytic method,and the heat density function and superficial heat density function of the flat milling insert and the waved-edge milling insert, whose rake face is wave curve plane and created by the authors using the diathermanous theory. We describe the mathematic model of the instantaneous temperature field by the theory of the finite moving planar sources of heat. At last, a program was done to calculate the heat density function and the milling temperature field. According to the calculated results and plotted graph, it is proven that the highest temperature is not on the knifepoint and host edge, in fact, it is offset from the host edge a certain space. So we can make the conclusion that the waved-edge milling insert’s cutting capability is higher than the flat milling insert’s which is consistent with the experimental result. All the studies above are the foundation for accurately describing the 3-D temperature field and optimizing groove.

Study on Simulation System of Cut-In Disrepair for the Milling Insert with 3D Complex Groove

The waved-edge milling insert is a kind of insert with 3D complex groove; its cut-in style and cut-in disrepair are different from the flat-groove insert. For researching the relationship between the cut-in style and the cut-in disrepair of the waved-edge milling insert, the cut-in simulation system of the waved-edge milling insert is developed, on the software of UG/Open API combined with VC++. By given different cut-in style parameters, the virtual cut-in process is founded and the proof is supplied for judging cut-in style and studying cut-in disrepair.

A Cutting Process Parameter Optimization Expert System for Difficult-to-Cut Materials

Focusing on the machining complexity of large containers where difficult-to-cut materials are used a lot, a cutting process parameter optimization expert system for difficult-to-cut materials is constructed based on experts’ knowledge and computer soft wares (VC++ 6.0and SQL Server 2000). In this paper, we made construction analysis and module design for the expert system, then constructed the knowledge base according to certain constraint models, and realized the functions of every module of the expert system by using the forward inference. This expert system can play a scientific direction role in the process parameters selection for cutting large containers.

Groove Optimization and Finite Element Analysis for Different Groove Milling Insert

Based on the experiments on milling the 45 steel with several types of different grooves milling inserts, this article has groove optimization and finite element analysis for different groove milling inserts. With the milling force testing system and orthogonal experimental design method, we have experiments with five types of different groove milling inserts for machining the 45 steel and compare their cutting capability, and the different grooves milling inserts are optimized. Based on the experiments, we have stress field analysis for different grooves milling inserts with finite element analysis method. The finite element analysis results are consistent with the experiment results well. All these studies provide the theoretic and experimental bases for groove development and groove optimization technology.

Experiment Study on Cutter Disrepair Principle and Optimization for Machining Heat-Resistant Steel

In order to find out the cutter disrepair principle and provide a valuable reference for the design, production and use of the heavy-duty hard alloy cutter, have experiment study on machining the heat-resistant steel-the 3Cr-1Mo-1/4Vsteel. First, have impact disrepair experiments with several types of different grooves milling inserts, and find out the difference of the impact disrepair invalidation types among them, and build the impact disrepair life cumulating distribution function mathematic model. Second, based on the adhering disrepair experiments, find out the difference of the adhering disrepair invalidation types, build the quantitative mathematic relation between milling temperature and maximal adhering disrepair depth on rake face of the cutter, and analyze the rule that the milling temperature affects the adhering disrepair. And then, on the basis of the scene machining, have analysis on cutter disrepair phenomenon and mechanism under the joint action of force and heat, so to provide a theoretical basis on how to avoid premature failure of the tool for the actual production process.

Experiment Study on Disrepair Principle for the Waved-Edge Milling Insert with Complex 3D Grooves

The impact disrepair and adhering disrepair of milling insert are the important factors that affect the normally running of the automated processing system. Based on machining the 45 steel, find out the difference of the impact disrepair invalidation types between the waved-edge milling insert and flat rake milling insert, build the impact disrepair life cumulating distribution function mathematic models by the mathematics statistic method and have contrast analysis of the impact disrepair average lives between them. Based on the experiments on milling the 3Cr-1Mo-1/4Vsteel, find out the difference of the adhering disrepair invalidation types between them, build the quantitative mathematic relation between milling temperature and maximal adhering disrepair depth on rake face, and analyze the rule that the milling temperature affects the adhering disrepair. All these studies provide the theoretic and experimental bases for the groove optimization.

Study on Dynamic Equation of Cut-In Contact for the Waved-Edge Milling Insert with 3D Complex Groove

Cut-in disrepair of milling inserts are closely related to dynamic equation of cut-in contact. According to the problem of serious cut-in disrepair, dynamic equation of cut-in contact for the waved-edge milling insert with 3D complex groove is studied. Rake face function of 3D complex groove waved-edge milling inserts is founded. Rake face equation of 3D complex groove inserts is founded. Rake face motion equation of 3D complex groove inserts is deduced. Appearance equation of workpiece machining region is deduced. Contact line (LM) equation is deduced, which is the contact line between rake face and workpiece cut-in side surface when rake face moving. Intersection line (C1D1) equation is deduced, which is the intersection line of cutting surface and side surface of workpiece. All the production above are the theory foundation for further researching the relationship between the cut-in style and cut-in disrepair, cut-in style optimization, 3D complex groove insert optimization.

Analysis and Study on Single Physics Field and Coupling Field of Cutting Tools for Machining Carbon Structural Steel

Based on the experiments on milling the carbon structural 45 steel with the flat rake milling insert and the waved-edge milling insert, the analysis and study on single physics field and coupling field are studied. On the basis of the milling force and milling temperature mathematical models, the force density function and heat density function of the waved-edge milling insert are built, the stress fields analysis and temperature fields analysis have been done. In order to discuss the distribution principle of equivalent stress and distortion under coupling condition, the coupling analysis on the stress field and temperature field is done. All these studies provide the theoretic and experimental basis for solving the cutter disrepair and groove optimization technology.

Study on Object Function of Milling Insert Impact Disrepair Based on Stress Field Analysis

This article takes the waved-edge milling insert (the rake face is curve plane) developed by Harbin University of Science and Technology as an example, as the goal of minimal impact disrepair, the optimization object function of the milling insert grooves is studied. Based on the force density function of the 3D complex groove milling insert, we have the finite element analysis on the stress fields of different cutting parameters, and have fuzzy synthetical judgement on the stress fields with fuzzy mathematic theory. We build the object function relation between the fuzzy synthetical judgement results and cutting parameters of the impact disrepair, so to have groove design optimization. All these studies provide the theoretic basis for the groove exploitation and the cutter disrepair which is the key problem in the automatization production and groove optimization.