Zhen Tong

Kinematics Error Compensation for a Surface Measurement Probe on an Ultra-Precision Turning Machine

In order to enhance the measurement availability for manufacturing applications, on-machine surface measurement (OMSM) is integrated onto the machine tools, which avoids the errors caused by re-positioning workpieces and utilizes the machine axes to extend the measuring range as well. However, due to the fact that measurement probe actuation is performed using the machine tool axes, the inherent kinematics error will inevitably induce additional deviations onto the OMSM results. This paper presents a systematic methodology of kinematics error modelling, measurement, and compensation for OMSM on an ultra-precision turning lathe. According to the measurement task, a selective kinematics error model is established with four primary error components in the sensitive measurement direction, based on multi-body theory and a homogeneous transformation matrix (HTM). In order to separate the artefact error from the measurement results, the selected error components are measured using the reversal method. The measured error value agrees well with the machine tool’s specification and a kinematics error map is generated for further compensation. To verify the effectiveness of the proposed kinematics error modelling, measurement, and compensation, an OMSM experiment of an optically flat mirror is carried out. The result indicates the OMSM is the superposition of the sample surface form error and the machine tool kinematics error. With the implementation of compensation, the accuracy of the characterized flatness error from the OMSM improves by 67%.

Review on FIB-induced damage in diamond materials

Background: Although various advanced FIB processing methods for the fabrication of 3D nanostructures have been successfully developed by many researchers, the FIB milling has an unavoidable result in terms of the implantation of ion source materials and the formation of damaged layer at the near surface. Understanding the ion-solid interactions physics provides a unique way to control the FIB produced defects in terms of their shape and location. Methods: We have carefully selected peer-reviewed papers which mainly focusing on the review questions of this paper. A deductive content analysis method was used to analyse the methods, findings and conclusions of these papers. Based on their research methods, we classify their works in different groups. The theory of ion-matter interaction and the previous investigation on ion-induced damage in diamond were reviewed and discussed. Results: The previous research work has provided a systematic analysis of ion-induced damage in diamond. Both experimental and simulation methods have been developed to understand the damage process. The damaged layers created in FIB processing process can significantly degrade/alter the device performance and limit the applications of FIB nanofabrication technique. There are still challenges involved in fabricating large, flat, and uniform TEM samples in undoped non-conductive diamond. Conclusions: The post-facto-observation leaves a gap in understanding the formation process of ioninduced damage, forcing the use of assumptions. In contrast, MD simulations of ion bombardment have shed much light on ion beam mixing for decades. These activities make it an interesting and important task to understand what the fundamental effects of energetic particles on matter are.