In this work, we introduce mechanistic considerations in nonlinear milling of particulate material. We show that the mobility of the powder can have a significant effect on the breakage frequency. During grinding, the change in particle size leads to changes in the mobility of the powder which in turn alters the breakage rate. The mechanistic modeling, being able to accommodate different respon...

Grinding can introduce surface and subsurface damage into ceramics, which may reduce the load-bearing area, and thus the residual strength of a ground component. In this study, the principle of continuum damage mechanics (CDM) is applied to predicting grinding damage for ceramics. A nonlinear thermodynamic constitutive model is established to describe the response of ceramics to complex grindin...

Grinding is an advanced machining process for the manufacturing of valuable complex and accurate parts for high added value sectors such as aerospace, wind generation, etc. Due to the extremely severe conditions inside grinding machines, critical process variables such as part surface finish or grinding wheel wear cannot be easily and cheaply measured on-line. In this paper a virtual sensor for...

In part I of this study we aim to evaluate and control the characteristics of the powders constituting the solid phase of a vaterite CaCO(3)-dicalcium phosphate dihydrate cement using a co-grinding process and to determine their impact on cement setting ability. An original methodology involving complementary analytical techniques was implemented to thoroughly investigate the grinding mechanism...

Neat grinding and solvent-drop grinding methods are found to be effective screening tools for indicating the potential for crystalline salt formation involving a given acid-base pair, as demonstrated with two model pharmaceuticals.

Path planning for a robot-assisted surface finishing system with an active torque controller is presented in this paper. We utilize a dexterous manipulator to attain the desired position and orientation in three-dimensional space during finishing processes. A single-axis active controller consists of a dc motor and a software observer is attached to the robot wrist and used to actuate a pneumat...

The sea urchin tooth is a remarkable grinding tool. Even though the tooth is composed almost entirely of calcite, it is used to grind holes into a rocky substrate itself often composed of calcite. Here, we use 3 complementary high-resolution tools to probe aspects of the structure of the grinding tip: X-ray photoelectron emission spectromicroscopy (X-PEEM), X-ray microdiffraction, and NanoSIMS....

In many process control applications, the system under consideration is compart-mental and positive. This means that the system satisfies a mass conservation condition and that both the state variables and the control input are physically constrained to remain non-negative along the system trajectories. For such systems, the design of state feedback controllers makes sense only if the control f...

SGS implemented two rules-based fuzzy logic expert applications on two grinding circuits operated by Peñoles Group in Mexico. Both expert systems are based on control strategies that push against process constraints to improve throughput. Based on proven methodologies, the projects also required some new approaches that led to permanent changes to the mill control strategy. This paper provides ...