Statistical Models in Engineering

Missing link

Compared to conventional machining (CM), ultrasonic vibration-assisted machining (UVAM) with high-frequency and small-amplitude has exhibited good cutting performances for advanced materials. In recent years, advances in ultrasonic generator, ultrasonic transducer, and horn structures have led to the rapid progress in the development of UVAM. Following this trend, numerous new design requirements and theoretical concepts have been proposed and studied successively, however, very few studies have been conducted from a comprehensive perspective. To address this gap in the literature and understanding the development trend of UVAM, a critical overview of UVAM is presented in this study, covering different vibration-assisted machining styles, device architectures, and theoretical analysis. This overview covers the evolution of typical hardware systems used to achieve vibratory motions from the one-dimensional UVAM to three-dimensional UVAM, the discussion of cutting characteristics with periodic separation between the tools and workpiece and the analysis of processing properties. Challenges for UVAM include ultrasonic vibration systems with high power, large amplitude, and high efficiency, as well as theoretical research on the dynamics and cutting characteristics of UVAM. Consequently, based on the current limitations and challenges, device improvement and theoretical breakthrough play a significant role in future research on UVAM.

Review of ultrasonic vibration-assisted machining in advanced materials

Advances in material and friction data for modelling of metal machining

Textured grinding wheels (TGWs) are wheels that have both specially-designed active and passive grinding areas on their geometrically active surfaces. The active area allows TGWs to perform the intermittent grinding process such that total wheel-workpiece contact time, average grinding forces and temperature in the cutting zone can be reduced. The passive area (or textures) refers to the non-grinding area where no grain is located at and the main functions of it include serving as reservoirs to transport more coolants/lubricants into the grinding zone and providing larger chip disposal space. With the increasingly demanding requirements from industries, the continuous evolution of TGWs has been enforced. However, to the best of the authors' knowledge, no comprehensive review on TGWs has been reported yet. To address this gap in the literature, this paper aims to present an informative literature survey of research and engineering developments in relation to TGWs, define and categorise TGW concepts, explain basic principles, briefly review the concept developments, discuss key challenges, and further provide new insights into understanding of TGWs for their advanced future engineering applications.

Textured grinding wheels: A review

Grinding is one of the most important manufacturing processes, especially when high surface qualities have to be realized or if hard or brittle materials have to be machined. Often the grinding performance is limited by workpiece failure due to a high thermal load in the contact zone. Therefore structured or patterned grinding wheels are frequently used to reduce the thermal load in the contact zone. In this paper a new patterning method will be introduced by using a fly-cutting kinematic for the structuring process. In face grinding experiments the patterned grinding wheels showed great potential to enhance the overall grinding performance by significantly decreasing process forces and grinding burn. The reduction of the thermal load in the contact zone can be explained by an improved coolant flow through the contact zone, which was measured with a specially designed coolant collecting bin.

Grinding with patterned grinding wheels

Design of bronze-bonded grinding wheel properties

In this paper, a new and innovative method for the patterning of grinding wheels is presented. The patterns are machined with a patterning tool by using fly-cutting kinematics. By changing the patterning process parameters, different pattern sizes and densities can be machined in a flexible way. Surface and cylindrical grinding experiments show that grinding with patterned grinding wheels can significantly reduce process forces, grinding burn, and grinding power. The surface roughness increases because less active cutting edges remain when grinding with patterned wheels. But especially for roughing processes, the results show great potential for increasing the overall grinding performance.

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Thilo Grove

Papers

Grinding with patterned grinding wheels

Design of bronze-bonded grinding wheel properties

Enhanced grinding performance by means of patterned grinding wheels

Basic principles for the design of cutting edge roundings

Differences and similarities between the induced residual stresses after ball end milling and orthogonal cutting of Ti–6Al–4V