Micro milling cutters or micro mills are unique and important micro tools for fabricating miniaturised devices with sufficient geometrical and dimensional accuracy and machined surface integrity. Micro milling cutters, compared to conventional macro tools, have significantly different material removal mechanisms. They are also made of different raw materials and structures and exhibit distinctive machining characteristics and performances. Herein, we present the first comprehensive and up-to-date review of micro milling cutters in terms of their uniqueness, material removal mechanisms, materials and compositions, structures and design, fabrication techniques and machining performances, to provide adequate guidance for interested involvers. We also outline and discuss several possible future research directions to offer potential insights for the micro milling community and future researchers.

Advances in micro milling: From tool fabrication to process outcomes

Health, work performance, and risk of infection in office-like environments: The role of indoor temperature, air humidity, and ventilation.

Multiphase coupling mechanism of free surface vortex and the vibration-based sensing method

On the higher-order thermal vibrations of FG saturated porous cylindrical micro-shells integrated with nanocomposite skins in viscoelastic medium

As a starting point in equipment manufacturing, sawing plays an important role in industrial production. Intelligent manufacturing equipment is an important carrier of intelligent manufacturing technologies. Due to the backwardness of intelligent technology, the comprehensive performance of sawing equipments in China is obviously different from that in foreign countries. State of the art of advanced sawing equipments is investigated along with the technical bottleneck of sawing machine tool manufacturing, and a new industrial scheme of replacing turning-milling by sawing is described. The key technologies of processing-measuring integrated control, multi-body dynamic optimization, the collaborative sawing network framework, the distributed cloud sawing platform, and the self-adapting service method are analyzed; with consideration of the problems of poor processing control stableness, low single machine intelligence level, no on-line processing data service and active flutter suppression of sawing with wide-width and heavy-load working conditions. Suggested directions for further research, industry implementation, and industry-research collaboration are provided.

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Key Technologies and Development Trends in Advanced Intelligent Sawing Equipments

A modal analysis of vibration response of a cracked fluid-filled cylindrical shell

The resuspension of indoor particulate matters caused by people indoor walking could affect indoor air quality and human health. Therefore, it is particularly important to study the resuspension rules of the particulate matters in different indoor environments. The influence of the ground material and the relative humidity on resuspension of the particulate matters were investigated under three kinds of ground materials and three different relative humidity. Results showed that different relative humidity and different ground materials had different effects on the mass concentration of the particulate matters. In addition, different particle sizes had diverse influence on the mass concentration. Compared with low-level loop pile carpet and shaggy carpet, hardwood floor was more conductive to human health which was less likely to cause the resuspension of the particulate matters. At the same time, relative humidity had a great influence on the resuspension of the particulate matters. With the increase of relative humidity, the resuspension rate of fine particulate matters decreased.

The influence of relative humidity and ground material on indoor walking-induced particle resuspension.

Experimental study on the influence of footstep motion on resuspension of particles in small box

In order to explore the cause of particle resuspension by footsteps, a footstep motion model was developed. The transient calculation method is used to simulate the resuspension of particles around footsteps. The particles are tracked by Discrete Random Walk (DRW) model based on Lagrange method. The Discrete Phase Model (DPM) is used to release particles in the simulation. The vortex, velocity vector, streamline diagram and particle motion were analyzed by numerical simulation. The results show that the footsteps cause resuspension of particles. At high footstep velocity, vortices are generated. The vortices occur at the periphery of the footsteps, and the air flow in the whole space is more symmetrical. Over time, during the whole footsteps, the vortices experience the process of occurrence, growth and annihilation. Due to the vortex in the air, the particles originally deposited on the ground will resuspend.

Shuihua Zheng

Papers

A modal analysis of vibration response of a cracked fluid-filled cylindrical shell

The influence of relative humidity and ground material on indoor walking-induced particle resuspension.

Experimental study on the influence of footstep motion on resuspension of particles in small box

Simulation of Particle Resuspension Caused by Footsteps