Papers by Author: Bin Li

Abstract: Cutting forces modeling is the basis to understand, simulate milling process and further to control milling process parameters for obtaining higher precision workpieces. With the development of engineering technology, FEM can be used to simulate metal machining process and gain better understanding of material flow within dies, so as to optimize tooling to eliminate tears, laps and other forging defects. In this paper, the calculated cutting force increases approximately logarithmically with the cutting speed, as should be expected from the logarithmic rate dependence.

Abstract: The characteristics of dynamic and static component of the cutting force signal were analyzed when the coated tool was used to cut gray cast iron. It is found that the whole and local of dynamic cutting force signal has self-similarity. Then the dynamic fractal dimension D was extracted by means of fractal theory, and the feature quantity M was extracted from the static cutting force signal. Research shows that the dynamic fractal dimension D of cutting force signal and static characteristic quantity M are varied with the cutting time. Their varying laws can be used to monitor the wear condition of coated tool effectively.

Abstract: Though titanium alloys are being increasingly sought in a wide variety of engineering and biomedical applications, their manufacturability, especially machining and grinding imposes lot of constraints. With the development of engineering technology, FEM can be used to simulate metal machining process and gain better understanding of material flow within dies, so as to optimize tooling to eliminate tears, laps and other forging defects. In this paper, numerical simulation was conducted by using FEM software on the whole cutting process for TC4 alloy mounting parts in an effort to investigate the metal flow behavior. The calculated cutting force increases approximately logarithmically with the cutting speed, as should be expected from the logarithmic rate dependence.

Abstract: Particle reinforced ceramics can be fabricated by a variety of methods, some of which have their origins in early civilization. The key objective of sintering studies is therefore to understand how the processing variables influence the microstructure evolution. In this way, useful information can be provided for the practical effort of designing processing conditions for producing the required microstructure.

Abstract: With the development of engineering technology, FEM can be used to simulate metal machining process and gain better understanding of material flow within dies, so as to optimize tooling to eliminate tears, laps and other forging defects. In this paper, numerical simulation was conducted by using FEM software on the whole cutting process for TC4 alloy mounting parts in an effort to investigate the metal flow behavior. The thermal simulation results obtained were compared with the cutting temperature and discussed in terms of literature data.

Abstract: This paper investigates a three-dimensional finite element model for the cross-wedge rolling process has been used to characterize the workpiece material stress and deformation behavior. Considering the characteristic of cross wedge rolling, the static implicit FEM program is selected. To simulate all forming stages in the cross wedge rolling process, dynamic adaptive remeshing technology was applied. Examples of numerical simulation for strain, stress distributions and rolling load components have been included. The stress distributions in the cross-section of the forming workpiece are analyzed to interpret fracture or rarefaction at the center of workpiece. The computer codes in finite element method can be used for a large variety of problems by simply changing the input data.

Abstract: As one of the most commonly used titanium alloys, TC4 (Ti6Al4V) has an alpha–beta structure and is widely used for aircraft components. In this study, numerical simulation was conducted by using FEM software on the whole cutting process for TC4 alloy mounting parts in an effort to investigate the metal flow behavior. This study not only helps to understand but also to improve and optimize cutting process, which are based on experience combined with a trial-and-error approach.

Abstract: In the milling process, the particles experience mechanical stresses at their contact points due to compression, impact, or shear with the mill medium or with other particles. The rate of grinding depends on a number of factors, including the mill parameters, the properties of the grinding media, and the properties of the particles to be ground. SEM photomicrographs show that the mean sizes of final refined powders are about 200–400 nm, and are quite uniformly distributed by wet ball milling, so the quasi-nano powders are very suitable for sintering.

Abstract: Milling of titanium alloy is usually a finishing process, therefore stable cutting process must be guaranteed at first. Temperature distributions were studied in this paper with the help of finite element method (FEM) for its significant influence on the quality of machined part. In this paper, numerical simulation was conducted by using FEM software on the whole cutting process for TC4 alloy mounting parts in an effort to investigate the metal flow behavior. The thermal simulation results obtained were compared with the cutting temperature.

Abstract: A toughening model of crack bridging reinforced ceramic matrix composites is presented. It was shown that this transition closely relates to the extent of toughness, particle size or volume fraction, and the particle yield stress. The constitutive equation is obtained through micromechanical considerations based on crack bridging toughening. The results show that the model is in good agreement with SEM results.