Sawing Force Prediction Model and Experimental Study on Vibration-Assisted Diamond Wire Sawing

At a Glance

Metadata	Details
Publication Date	2022-11-19
Journal	Micromachines
Authors	Chenpu Zhang, Zhikui Dong, Yanheng Zhao, Ziliang Liu, Shang Wu
Institutions	Yanshan University
Citations	6
Analysis	Full AI Review Included

Technical Documentation & Analysis: Vibration-Assisted Diamond Wire Sawing

Executive Summary

This analysis summarizes the findings of the research on Vibration-Assisted Diamond Wire Sawing (VADWS) for brittle materials, highlighting the direct relevance to 6CCVD’s high-precision CVD diamond materials and engineering services.

Core Innovation: VADWS was successfully applied to hard, brittle materials (SiC, NdFeB, HT250) to establish a macroscopic sawing force prediction model and optimize slicing parameters.
Quantifiable Force Reduction: Sawing forces ($F_{nv}$ and $F_{tv}$) were reduced by approximately 20% when operating at the maximum tested vibration frequency of 50 Hz.
Surface Quality Improvement: Vibration assistance significantly reduced surface roughness (Ra, Rz) and geometric variations (Total Thickness Variation, TTV, and Warp).
Precision Metrics: Maximum TTV for SiC slices was reduced from 0.049 mm (conventional) to 0.018 mm (VADWS), demonstrating improved stability and slice quality.
Mechanism Insight: The vibration assistance enhances the polishing effect of the abrasive diamond particles, leading to improved chip removal and reduced subsurface damage.
Material Relevance: The study focuses on materials central to high-tech industries (SiC, NdFeB), directly aligning with the target markets for 6CCVD’s Single Crystal Diamond (SCD) and Polycrystalline Diamond (PCD) products.

Technical Specifications

The following hard data points were extracted from the experimental design and results, focusing on the optimized parameters and performance metrics achieved using VADWS.

Parameter	Value (Range)	Unit	Context
Vibration Frequency ($f$)	0 to 50	Hz	Optimal force reduction achieved at 50 Hz.
Wire Speed ($v_{\tau}$)	10.0 to 20.0	m/s	Sawing force decreased with increasing wire speed.
Feed Speed ($v_n$)	40 to 60	mm/h	Sawing force increased with increasing feed speed.
Wire Tension ($F$)	20 to 40	N	Sawing force increased with increasing wire tension (under vibration).
Wire Radius ($r$)	0.05 to 0.15	mm	Range of fixed abrasive diamond wire used.
Sawing Force Reduction	~20	%	Achieved for both normal ($F_{nv}$) and tangential ($F_{tv}$) forces at 50 Hz.
HT250 Average Ra (No Vib)	453	nm	Baseline surface roughness (HT250).
HT250 Average Ra (With Vib)	336	nm	Surface roughness optimized by VADWS.
SiC Max TTV (No Vib)	0.049	mm	Maximum Total Thickness Variation (SiC multi-wire slicing).
SiC Max TTV (With Vib)	0.018	mm	Maximum TTV achieved with 50 Hz vibration assistance.

Key Methodologies

The experimental study utilized a DX-2260 multi-wire sawing machine tool equipped with a custom vibration-assisted platform (servo motor and eccentric device) to control the ingot motion along the wire speed direction.

Material Selection: Experiments were conducted on HT250 (cast iron), Stainless Steel, NdFeB, and SiC ingots, all prepared via aging treatment and cut into square shapes.
Vibration Application: A simple harmonic vibration was applied to the working table carrying the ingot, along the direction of the wire speed, with frequencies ranging from 0 to 50 Hz.
Force Measurement: A 3D force sensor was mounted beneath the working table to measure the normal ($F_{nv}$) and tangential ($F_{tv}$) sawing forces during single-wire experiments. Wire tension ($F$) was measured using a tension sensor on the guide wheels.
Sawing Force Modeling: A macroscopic sawing force prediction model was established based on kinematic characteristics, impact load, and abrasive particle sawing depth, and verified against experimental data (average relative error < 10.63%).
Surface Quality Analysis (Single-Wire): Surface roughness (Ra, Rz), roughness profile, waviness profile, and thickness profile were scanned using a Bruker Dektak XT instrument.
Geometric Quality Analysis (Multi-Wire): Total Thickness Variation (TTV) and Warp of the resulting slices (NdFeB and SiC) were measured to evaluate overall surface quality and sawing stability.

6CCVD Solutions & Capabilities

The research demonstrates the critical need for high-stability, ultra-hard materials and precision metrology in advanced slicing applications like VADWS. 6CCVD is uniquely positioned to supply the foundational diamond materials and custom engineering required to replicate, optimize, and scale this technology.

Applicable Materials for Tooling and Metrology

The VADWS process relies on fixed abrasive diamond wire to slice extremely hard materials (SiC, NdFeB). 6CCVD provides the highest quality CVD diamond materials essential for the associated tooling, fixtures, and metrology standards.

Application Requirement	6CCVD Material Recommendation	Key Capability Match
High-Precision Fixtures/Jigs	Optical Grade SCD (Single Crystal Diamond)	SCD offers extreme hardness and thermal stability, ideal for reference surfaces or fixtures that must withstand high-frequency vibration without deformation.
Wear-Resistant Tooling	High-Purity PCD (Polycrystalline Diamond)	PCD plates (up to 125mm) provide superior wear resistance for components subject to abrasive slurry or high contact stress in the sawing environment.
Metrology Standards	Polished SCD/PCD Substrates	Required for calibrating the Bruker Dektak XT or other instruments measuring Ra < 1nm. Our SCD polishing achieves Ra < 1nm.
Conductive Applications	Boron-Doped Diamond (BDD)	If electro-chemical assistance or integrated sensing is required in future VADWS designs, BDD offers stable conductivity.

Customization Potential

The VADWS research highlights the importance of precise ingot dimensions and specialized experimental setups (e.g., 22mm x 430mm SiC ingots). 6CCVD’s manufacturing capabilities directly support the customization needs of R&D and production engineers:

Custom Dimensions: We offer PCD plates and wafers up to 125mm in diameter, and custom substrates up to 10mm thick, allowing for the fabrication of large, stable tooling components.
Ultra-Low Roughness: Our in-house polishing capability achieves surface roughness of Ra < 1nm for SCD and Ra < 5nm for inch-size PCD, ensuring that reference surfaces and metrology standards meet the stringent requirements of TTV/Warp analysis.
Integrated Metalization: For advanced sensor integration or specialized fixturing, 6CCVD provides custom metalization services (Au, Pt, Pd, Ti, W, Cu) directly onto the diamond material.

Engineering Support

The optimization of VADWS involves complex interactions between material properties, vibration parameters, and mechanical forces. 6CCVD’s in-house PhD team specializes in the tribology and mechanical properties of diamond and brittle materials.

Material Selection Consultation: Our experts can assist researchers in selecting the optimal CVD diamond grade (SCD vs. PCD) and geometry for tooling used in similar brittle material slicing projects (e.g., SiC, Sapphire, NdFeB).
Process Optimization: We provide technical guidance on how the intrinsic properties of CVD diamond (e.g., stiffness, thermal conductivity) can be leveraged to maximize sawing stability and minimize TTV/Warp in high-frequency vibration environments.

For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly.

View Original Abstract

Diamond wire sawing is the main machining technology for slicing various brittle materials, such as crystalline silicon, SiC, and NdFeB. Due to their high hardness and high brittleness, as well as the ease with which the surfaces of machined materials are damaged, it is difficult to further improve the sawing efficiency and the surface quality based on research conducted on the original machining method. In this paper, a vibration-assisted diamond wire sawing method is proposed. We analyzed the impact of load on the ingot, motion trajectory, and sawing depth of the abrasive particles, and a macroscopic sawing force prediction model for the vibration-assisted sawing method was established and verified via experiments. Based on the single-wire-sawing experiment and prediction model, the influences of the vibration parameters and sawing parameters on the sawing force were determined. The influences of vibration assistance on the surface quality, including the roughness profile, waviness profile, thickness profile, Ra, and Rz, were explored through single-wire-sawing experiments, and the influences of vibration assistance on the geometric parameters of slices, such as the total thickness variation (TTV) and warp, were explored through multi-wire-sawing experiments. It was found that vibration-assisted sawing can reduce sawing force and improve surface quality.

Tech Support

Original Source

DOI: https://doi.org/10.3390/mi13112026

References

2013 - Comparative Analysis of Fracture Strength of Slurry and Diamond Wire Sawn Multicrystalline Silicon Solar Wafers [Crossref]
2017 - The chemo-mechanical effect of sawing fluid on material removal in diamond scribing of silicon [Crossref]
2019 - Material removal and surface generation mechanisms in diamond wire sawing of silicon crystal [Crossref]
2003 - Fixed abrasive diamond wire machining—Part II: Experiment design and results [Crossref]
2004 - Fixed abrasive diamond wire saw slicing of single-crystal silicon carbide wafers [Crossref]
2004 - Development of endless diamond wire saw and sawing experiments [Crossref]
2020 - Characterization of electroplated diamond wires and the resulting ingot quality in silicon sawing [Crossref]
2017 - An Experimental Research on the Force and Energy During the Sapphire Sawing Using Reciprocating Electroplated Diamond Wire Saw [Crossref]
2017 - Prediction of sawing force for single-crystal silicon carbide with fixed abrasive diamond wire saw [Crossref]
2017 - A scratching force model of diamond abrasive particles in wire sawing of single crystal sic [Crossref]