Material flow

About: Material flow is a research topic. Over the lifetime, 3050 publications have been published within this topic receiving 36844 citations. The topic is also known as: material stream.

On the steady-state workpiece flow mechanism and force prediction considering piled-up effect and dead metal zone formation

Abstract: The manufacturing of miniaturized components is indispensable in modern industries, where the uncut chip thickness (UCT) inevitably falls into a comparable magnitude with the tool edge radius. Under such circumstances, the ploughing phenomenon between workpiece and tool becomes predominant, followed by the notable formation of dead metal zone (DMZ) and piled-up chip. Although extensive models have been developed, the critical material flow status in such microscale is still confusing and controversial. In this study, a novel material separation model is proposed for the demonstration of workpiece flow mechanism around the tool edge radius. First, four critical positions of workpiece material separation are determined, including three points characterizing the DMZ pattern and one inside considered as stagnation point. The normal and shear stresses as well as friction factors along the entire contact region are clarified based on slip-line theory. It is found that the friction coefficient varies symmetrically about the stagnation point inside DMZ and remains constant for the rest. Then, an analytical force prediction model is developed with Johnson-Cook constitutive model, involving calibrated functions of chip-tool contact length and cutting temperature. The assumed tribology condition and morphologies of material separation including DMZ are clearly observed and verified through various finite element (FE) simulations. Finally, comparisons of cutting forces from cutting experiments and predicted results are adopted for the validation of the predictive model. (Less)

Numerical and Experimental Investigation of the Innovatory Incremental-Forming Process Dedicated to the Aerospace Industry

Abstract: The main goal of this work is development of the incremental-forming (IF) process for manufacturing integral elements applicable to the aerospace industry. A description of the proposed incremental-forming concept based on division of large die into a series of small anvils pressed into the material by a moving roll is presented within this article. A unique laboratory device has been developed to investigate the effects of process parameters on the material flow and the press loads. Additionally, a developed numerical model of this process with specific boundary conditions is also presented and validated to prove its predictive capabilities. However, main attention is placed on development of the process window. Thus, detailed investigation of the process parameters that can influence material behavior during plastic deformation, namely, roll size and roll frequency, is presented. Proper understanding of the material flow to improve the IF process, as well as press prototype, and to increase its technological readiness is the goal of this article. Results in the form of, e.g., strain distribution or recorded forging loads are presented and discussed.