AI summary

75% confidence

This study investigates the tribological behavior and material removal mechanisms of sapphire lapping using HFCVD diamond-coated tools with spherical, pyramidal, and prismatic surface textures. The research establishes three distinct material removal models based on experimental results, highlighting how coating morphology influences surface finish and removal rates.

Generated by MESSAI extraction pipeline · review against source PDF

Extraction

Reported parameters

No values extracted from this paper yet.

No 3D model is mapped to this paper yet. Parameter ranges above still place reported values on the literature distribution.

Abstract

Diamond coatings with three distinct surface textures, namely spherical, pyramidal, and prismatic morphologies, were fabricated using the hot-filament chemical-vapor deposition (HFCVD) method. Scanning electron microscopy (SEM) was employed to analyze the surface morphological characteristics and differences among the coatings. Raman spectroscopic analysis further confirmed that all three diamond films exhibited excellent deposition uniformity and high crystalline quality. A three-dimensional optical microscopy system was used to measure the surface roughness values, which were determined to be Ra 0.423 μm, Ra 0.515 μm, and Ra 0.809 μm, respectively. An HFCVD diamond-coated tool was innovatively employed for the lapping of sapphire wafers, enabling a systematic investigation of the tribological behavior during the lapping process. Based on the experimental results, three morphological material removal models were established. The study demonstrates that the spherical diamond coating achieves a superior surface finish (Ra 0.22 μm) due to its continuous multi-point contact geometry, governed by the agglomerated nanocrystalline structure. Sample 3 had the highest removal rate of 24.3 μm/min. This is related to its surface morphology characteristics and is also due to the two-body contact between the diamond-coated tool and sapphire, offering a high-efficiency alternative for precision machining.

Key findings

  • Spherical diamond coatings achieve a superior surface finish of Ra 0.22 μm due to continuous multi-point contact geometry governed by an agglomerated nanocrystalline structure.
  • Pyramidal and prismatic morphologies exhibit different roughness values (Ra 0.515 μm and Ra 0.809 μm respectively) prior to lapping.
  • The pyramidal morphology demonstrated the highest material removal rate of 24.3 among the tested samples.

Keywords

LappingSapphireSurface roughnessTribologyScanning electron microscopeDiamond

Identifiers

Journal
Materials
Year
2026