Design of Deterministic Microstructures as Substrate Pre-Treatment for CVD Diamond Coating

Abstract

The coating of highly stressed components with chemical vapor deposition (CVD) diamond can extend their lifetime. In particular, the combination of steel substrates with diamond layers would find many applications in industrial production. However, there are some challenges, for example, the high mismatch in the thermal expansion between steel and diamond, which commonly leads to the delamination of the coating. Thus, a pre-treatment of the substrate surface is needed. Particle blasting has been established in some studies as a suitable process. However, apart from particle residues in the surface of the substrate, these surfaces have a stochastic character, which limits their reproducibility and modification options. This paper presents some instructions for the recording and derivation of defined properties of those surfaces. The conversion of characteristic surface features into quantitative process parameters could serve as the foundation for the manufacturing of deterministic microstructures, especially those produced by ultrasonic vibration superimposed machining. This should increase the reproducibility and the possibilities of the modification with regard to the structural shaping of the functional surface. The design was developed using both a kinematic surface simulation tool as well as a finite elements analysis for the cooling process of the coating–substrate–composite. A high accordance with real finished surfaces was achieved.

A New Diamond Chemical Vapor Deposition Method on Steel Surface

“…( The results showed that residual stress could be relaxed by regular roughness. The reason for this stress relaxation is that the regular roughness enables the "elastic deformation" and a "mechanical interlock effect" of the steel substrate 18) . In the present experiment, a pit pattern was created by drill processing.…”

Elastic–Plastic Material Deformation and Conveying Value of Twist-Free Turned Surfaces

“…In order to minimize the computational effort, the tool can be described by a contour line along the corner geometry. Previous investigations revealed that the same simulation results could be obtained with such a simplified representation as long as a geometrical intersection of the flank face can be excluded [16]. Therefore, the geometrical extension of the intersecting tool body in the direction of the 𝑥-(𝛥𝑥) and 𝑦-axis (𝛥𝑦) (Figure 3c) needs to be considered.…”

“…The introduced twist-free surfaces can be characterized by the tool geometry and the kinematical process parameters of the lathe and the short-stroke drive system. A simulation model, developed in the software MATLAB R2019a (The MathWorks, Inc., Natick, MA, USA) and firstly introduced for vibration-imposed milling in [15] and [16], was extended for the prediction and evaluation of the kinematic surface structure and transition areas during SST. The kinematical approach subtracts the tool geometry along the tool trajectory with the workpiece surface, but it does not consider elastic-plastic effects such as burr formation or thermal expansion.…”

Finite Element Analysis of Plastic Deformation in Ultrasonic Vibration Superimposed Face Milling of Steel X46Cr13

“…ness and vibration amplitude and was already analyzed in [13]. There is a more distinct difference between the near-real numerical simulation and the real surfaces.…”

“…The spatial resolution of the workpiece and the tool is fixed and proportional to the simulation time and the imaging accuracy of the surface microstructure, while the temporal resolution depends on the process parameters. Therefore, the simulation model can automatically determine the minimum required time resolution based on the number of cuts per period and frequencies in the ultrasonic range [ 13 ].…”