Tungsten Carbide Tool Research Articles

Wear performance of nano-engineered boron doped graded layer CVD diamond coated cutting tool for machining of Al-SiC MMC

Machining of Al-SiC metal matrix composite (MMC) is still being a challenging task in the automotive and aerospace sector due to its frequent tool wear while processing this MMC. The hard Polycrystalline diamond tools (PCD) are used as a cutting tool in many sectors for machining of MMC. But the usage of PCD is commercially not viable due to its high cost involved in the fabrication. In this regard, low-cost diamond-coated tungsten carbide (WC-Co) tools are considered as an alternative to PCD. However, the diffusion of cobalt from WC-Co during diamond deposition promotes higher graphitization at the diamond-carbide interface. This induces coating delamination during MMC machining. This outward diffusion of cobalt can be hindered by doping boron in the diamond lattice to enhance adhesion strength of the coating. Hence in this work, the boron doped graded layer diamond coating (BDD/transition layer/NCD) on WC-Co was proposed to improve the machining performance of MMC. In this work, four different CVD diamond coated WC-Co tools such as microcrystalline diamond coating (MCD), nano-crystalline diamond coating (NCD), boron-doped diamond coating (BDD) were considered for comparison along with the proposed tools. The different phases (sp3 and sp2) in the diamond coating were analyzed through cross-sectional Raman mapping technique. The Rockwell indentation test confirms that the better adhesion strength obtained in BMTN coated tools. The wear behavior of these diamond coated tools was tested by machining of AA2124/25%SiCp material. In addition, performances of these tools were compared with widely accepted industrial grade PCD tools. The temperature at the cutting zone, chip morphology and surface roughness of the machined component were studied through an appropriate test method. The occurrence of edge chipping while machining was continuously monitored through acoustic emission (AE) signals. The machining results show that BMTN coated tool exhibits least tool wear (VB = 0.25 mm) in comparison with MCD (VB=0.47 mm), NCD (VB=0.57 mm), BDD (VB= 0.33 mm) coated tools and PCD (VB = 0.29 mm) tools respectively. In addition, the results of AE signals show that MCD, NCD coated tools and PCD tools undergone edge chipping whereas there was no edge chipping observed in BDD and BMTN tools. Thus Nano –Engineered BMTN tools observed to be a preferred cutting tool for efficient machining of Al-SiC MMC material.

Tool wear processes in low frequency vibration assisted drilling of CFRP/Ti6Al4V stacks with forced air-cooling

Drilling CFRP/Ti6Al4V stacks in one-shot time becomes essential in the modern aerospace manufacturing sectors in order to guarantee the productivity due to the demands of riveting and fastening assembly. In the present study, a novel integrated system of low frequency vibration assisted drilling (LFVAD) coupled with the forced air-cooling was designed to investigate the tool wear issues in drilling of CFRP/Ti6Al4V stacks. The used uncoated solid tungsten carbide tools were specially designed with threaded shanks for fitting the adapter of the LFVAD tool holder. Main geometrical features of the threaded shank drills include a 6.35 mm diameter, a 140° point angle, a 30° helix angle and two cutting edges. Drilling temperatures and forces were in-situ measured for the LFVAD subjected to varying conditions, and the results were compared with the conventional drilling under the identical drilling conditions. It is found that the small titanium chip segments produced by the interrupted cut of vibration drilling can be removed efficiently via the help of the forced air-cooling. Compared with the conventional drilling, slower flank wear rates and lower cutting temperatures are identified under the LFVAD with the forced air-cooling. The adhesive wear is the main wear mode for both drilling methods; however, the chemical wear becomes more pronounced while the cutting edge chipping predominates in the LFVAD. In sum, the LFVAD with the forced air-cooling is confirmed capable of improving the machinability of the CFRP/Ti6Al4V stacks from the aspects of reducing tool wear.

Characterization of abrasion- and dissolution-induced tool wear in machining

In the present work, a comparative study is reported on tool wear characteristics induced by machining two distinctively different types of materials: Vanadis 10 tool steel containing large amounts of MC and M7C3 carbides, and 316L austenitic stainless steel which is nearly free of hard abrasive phases. Tool life tests were conducted using cemented tungsten carbide tools (WC-Co), both uncoated and TiCN-Al2O3 coated. The subsequent wear characterization included scanning electron microscopy and electron backscatter diffraction (EBSD). Examination of worn WC-Co substrates and coatings revealed significantly different wear characteristics after machining the two workpiece materials. Predominantly abrasion-induced wear was revealed by micro-fragmented tool constituents as well as sub-micron sized grooves and ridges on tool substrates and coatings when machining the tool steel. Moreover, EBSD analysis indicated that the tool substrates exhibited significant superficial strains caused by localized plastic deformation during sliding contact of the tools with the carbides of the tool steel. In contrast, during machining of the stainless steel using uncoated tools, the predominantly dissolution-induced wear resulted in WC-Co substrates with smooth surfaces and absence of significant strain. The worn coatings showed signs of spalling of micro-fragments which indicated the dominant contribution of adhesive wear when machining stainless steel.

Enhancing dimensional accuracy and surface integrity by helical milling of carbon fiber reinforced polymers

Geometrical defects are one of the main problems in machining of carbon fiber reinforced polymer (CFRP) laminates Helical milling is a brand new machining process and a kind of manufacturing method that helical tool movement is added and results in better hole quality with one-time machining. In recent years, helical milling is attracting increasing attention of numerous researchers. In our study, an experimental investigation is carried out on CFRP laminates by using tungsten carbide tool. For the first time, effects of process parameters like cutting velocity and feed rate on the hole quality aspects such as hole diameter, circularity, cylindricity and surface roughness are experimentally and statistically discussed. Besides, surface morphology of the hole wall is examined. Analysis of variance (ANOVA) is carried out on hole quality parameters and their contribution rates are determined. Increasing cutting velocity improved hole diameter, circularity and cylindricity and had no significant influence on surface roughness. In addition, reduction in feed rate is suggested to have a high-quality hole in helical milling of CFRP. By statistical evaluation, results show that cutting velocity in all cases, is more effective than feed rate. Moreover, machining force is reduced in helical milling compared to conventional drilling.

Wear behavior of TiAlN coated WC tool during micro end milling of Ti-6Al-4V and analysis of surface roughness

The demand for high quality micro components has been on the upsurge for the past few decades. Nowadays micro end milling is preferred to produce 3D micro parts. This paper presents an investigation on wear behavior of solid tungsten carbide (WC) tool with TiAlN coating during micro end milling of Ti-6Al-4V. Miniaturization of the tool combined with machining of hard to machine material like Ti-6Al-4V results in rapid tool wear. Feed/tooth to tool edge radius ratio (f/r) has got significant influence on micro end milling machining mechanism. For f/r less than one, ploughing is dominant, and the shearing mechanism prevails when f/r is greater than one. Therefore, experiments were carried out at two feed rates 0.3 µm/tooth and 5 µm/tooth to examine the effect of tool edge radius on tool wear. Tool wear in terms of flank wear, adhesive wear, abrasive wear, enlargement of tool edge radius, and delamination of coating was studied, and an investigation on the effect of tool wear on surface roughness was also carried out. A 3D optical profilometer was used to characterize tool wear and surface finish of the machined feature. With 0.3 µm/tooth feed rate, tool fails after ~700 mm length of cut and with 5 µm/tooth feed rate, tool fails after ~1000 mm length of cut. For both 0.3 µm/tooth and 5 µm/tooth feed rates tool fail approximately at 15–20 µm flank wear width. Adhesive wear was found to be the major tool failure mechanism for both feed rates. Moreover, in micro end milling operation selecting a feed rate slightly above the tool cutting edge radius will be beneficial so that a good surface finish is obtained during initial stages of the wear.

Effects of deposition parameters on the structure and properties of ZrN, WN and ZrWN films

This paper examines optimal settings for deposition parameters for transition metal nitride (ZrN, WN and ZrWN) thin films that are deposited on tungsten carbide tools and glass substrates using direct current (DC) reactive sputtering with pure Zr and W metal targets and Ar plasma and $$\hbox {N}_{2}$$ reactive gases. Experiments using the grey-Taguchi method are conducted to study the effects of deposition parameters (substrate plasma etching time, $$\hbox {N}_{2}/(\hbox {N}_{2} + \hbox {Ar})$$ flow rate, deposition time and substrate temperature) on a film that is deposited on a cutting tool that is used for dry machining and on the films’ mechanical properties. The substrates’ surfaces are etched using oxygen plasma pretreatment. It is clear that the coated film is homogeneous, very compact and exhibits perfect adherence to the substrate. The results of grey relational analysis show for the dry turning AISI 304 stainless steel that the surface roughness is approximately $$R_{\mathrm{a}} = 0.70\, \, \upmu \hbox {m}$$ and that the flank wear is approximately $$14.02 \, \,\upmu \hbox {m}$$ . The grey relational analysis shows that the period for which the substrate (tungsten carbide tool) is under plasma-etched pretreatment has the most significant effect on both the surface roughness and flank wear. The coated films are analysed using scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), transmission electron microscopy (TEM), X-ray diffraction and a nano-indenter. The ternary nitride (ZrWN)-coated specimens exhibit better mechanical properties than binary nitride (ZrN and WN) specimens. The optimum ZrWN coating exhibits the greatest hardness (H), elastic modulus (E) and H / E values.

The fundamental mechanisms of wear of cemented carbide in continuous cutting of medical grade cobalt chromium alloy (ASTM F75)

Medical grade cobalt chromium alloys are one of a select number of material types approved for use in the components of orthopaedic implants. However, there has been minimal published research into the fundamental mechanisms in the cutting processes used in their manufacture. These processes affect the form accuracy, surface finish and integrity of these safety critical devices.The present work reports on a scientific investigation into the fundamental mechanisms of tool wear in continuous cutting of the biomedical grade Co-Cr-Mo ASTM F75 alloy using uncoated tungsten carbide tools. Confocal and scanning electron microscopy (SEM) is used to examine and characterise the progression of tool wear at intervals up to a defined “end of life limit” for each combination of speed (vc) and feed rate (f) in experiments where the range of these parameters vary from 20 to 60 m/min and 20–60 μm/rev respectively to reflect the ranges used in industry.An empirical model is then established for progressive tool wear which demonstrates that the wear rates vary by over an order of magnitude. The parameters for the Taylor equation are also determined for this material for the first time. Microscopic examination shows the presence of characteristic tool wear “zones” with consistent size, shape and composition. These zones evolve depending on combination of speeds and feeds as determined in the full factorial experiment. Detailed characterisation of the wear surfaces and cross sections provide a number of insights into the possible mechanisms of wear. It is hypothesised that micron thick layers of Co-Cr-Mo, found on the rake and flank wear surfaces, indicate primary wear mechanism involving adhesion of the work material and subsequent removal of WC hard particles by entrainment in the work material flow.

A Study of Minimum Quantity Lubrication (MQL) by Nanofluids in Orbital Drilling and Tribological Testing

In minimum quantity lubrication (MQL), an aerosol containing a minimum amount of the cutting fluid is delivered to the tool/workpiece interface during the metal cutting operation. The fluid lubrication by the fluid and the cooling by the compressed air in the aerosol improves the cutting process, while the low consumption rate in MQL provides less cleanup and reduces the associated cost. In this paper, molybdenum disulfide (MoS2) and hexagonal boron nitride (hBN) nanoparticles were added to the aerosol for providing a third functionality to the MQL, which is solid lubrication at the interface. Both orbital drilling and tribological testing using a four-ball tester were studied to examine the effectiveness of solid lubrication in MQL. In orbital drilling of titanium with tungsten carbide tools, MQL with nanofluids containing MoS2 nanoparticles resulted in less transfer film buildup on the tool. In four-ball testing, MQL with nanofluids with MoS2 and hBN nanoparticles yielded lower surface temperatures and less variation of frictional torques in titanium.

Experimental Investigation of High Speed Tool Rotation on Heat Affected Zone and Over Cut in ECDM

Abstract Micro-channeling and micro-engraving processes on the glass material are difficult using the conventional machining methods. Channeled parts of glass material are widely used in the micro electromechanical system (MEMS), biomedical applications, aerospace etc. Electrochemical discharge machining (ECDM) shows the potential of machining of non-conducting materials like glass, ceramics and composites. Formation of heat affected zone (HAZ) and over cut (OC) are the weakness in the ECDM engraving process. These weaknesses can be overcome with high speed electrochemical discharge machining (HSECDM) which has the ability to reduce the heat affected zone and over cut because of the higher tool rotation speed at different feed rate. This paper mainly concentrated on the engraving with high speed tool rotation and different feed rate, the experimental setup has been developed for the experimentation. In this study, engraving on the soda lime glass material is studied and tungsten carbide tool electrode of diameter 500 µm is used. The experimental result shows that with tool rotation speed and feed rate width of heat affected zone (HAZ) and over cut (OC) changes.

Machinability analysis and hybrid optimization during wet turning of SS304 using coated tools

Abstract In this work, SS304 has been machined using tungsten carbide tool inserts coated with multilayer of TiN/TiAlN under conventional wet cooling condition. Experiments have been conducted based on Taguchi robust technique with L9 orthogonal array. Effects of three important machining parameters cutting speed (CS), feed (F), and depth of cut (DC) on machinability aspects i.e. surface roughness (Ra) and material removal rate (MRR) have been investigated. Further, grey relational technique integrated with genetic algorithm (GA) was used for simultaneous optimization of MRR and Ra. It was observed that the optimized machining parameter setting for MRR and Ra is CS: 170 m/min; F: 0.2 mm/rev; and DC: 0.5 mm. The optimum values of MRR and Ra are 81.39 g/min and 3.14 µm respectively.

External force assisted electro discharge machining of SS 316

Abstract Hybrid electro discharge machining came into the scenario of macro machining due to the need of more rapid machining process with improved efficiency of non conventional machining process. Electro-Discharge Machining (EDM) is a kind of non conventional machining specially used for drilling the holes of required dimensions aspect ratio. Earlier, vibration assisted EDM had came into existence to improve the efficiency such as increase in the metal removal rate, reduction in the electrode wear rate, and decrease in radial overcut of the surface of machined workpiece. But this technique of vibration assisted EDM process did not proved to be successful due to some disadvantages like increase in tool wear for low melting and comparatively softer tool material. Also vibration of workpiece material affects the circularity of holes produced by EDM process. There always exist a need for more advanced hybridised process to improve the overall machining efficiency specially circular shape and radial overcut. In this paper, an external force assisted called permanent magnetic field force assisted EDM process has been carried out with tungsten carbide tool of 5 mm diameter and SS 316 plate of 1.6 mm thickness. Measured performance characteristics like electrode or tool wear rate and diametral overcut represented satisfactory results with permanent magnetic field induced EDM process. The effects on MRR, TWR and diamteral overcut of SS 316 have been analyzed by the related software. It has been found that tool wear and diametral overcut has been found to be reduced with magnetic field assisted EDM than conventional EDM process. Also, machining time is reduced to a certain extent with this new technique of hybridisation.

Wear Behaviour of Carbide Tool During Machining of Steel

Wear process takes predominant role in reducing the tool life during machining of steel. Tool wear is the progressive loss of material from the surface of the body of a tool. This occurs as a natural consequence when two surfaces with relative motion interact with each other. Challenges of wear mechanisms such as variation in chips, high pressure loads and spring back are responsible for tool wear. In addition the rate of tool wear depends on tool and work piece materials, tool shape, cutting fluids, process parameters (such as cutting speed, feed rate and depth of cut) and tool geometry and machine tool characteristics. The tool wear weight assesses real damage to the tool and is also based on blended wear of flank, crater, chip notching, primary and secondary grooving. This paper discusses the wear behavior of carbide tool utilizing response surface methodology. Machining tests were carried out by using EN-31 steel with tungsten carbide tools using soluble oil-water mixture lubricant under different machining variables. The study reveals that tool wear is mainly affected by cutting speed ,feed rate and tool nose radius whereas, depth of cut have negligible effect. However, response surface methodology combined with factorial design of experiments is a better alternative to the traditional one-variable- at –a-time approach for studying the effects of cutting variables on responses such as tool wear.

Microstructure and mechanical properties of friction-stir welded St52 steel joints

The aim of this work is to investigate the mechanical properties and microstructures of friction-stir welded (FSWed) St52 structural steel joints. In this study, St52 steel plates with a thickness of 4 mm were butt-welded by friction-stir welding (FSW) using a tungsten carbide tool having a conical pin. The microstructure of the welded zone consists of equiaxed fine ferrite, grain boundary ferrite, Widmanstatten ferrite, and aggregates of ferrite + cementite. The microhardness measurements showed that the hardness of the welded zone was significantly higher than that of the base metal. The FSWed St52 joint exhibited a significant strength overmatching in the weld region and a strength performance similar to or slightly higher than that of the base plate.

Investigations on Microstructural Evolutions and Mechanical Properties of Dual-Phase 600 Steel and AA6082-T6 Aluminum Alloy Dissimilar Joints Fabricated by Friction Stir Welding

In this research work, dual-phase 600 steel grade and AA6082-T6 aluminum alloy dissimilar flat plates of thickness 2 mm were fabricated by using friction stir welding. Three tool rotational speeds of 560, 710 and 900 rpm, three tool traverse speeds of 24, 32 and 40 mm/min, three tool offsets of 0.8, 1.3 and 1.8 mm and constant tool tilt angle of 0.5° were used to obtain the defect-free welds. Macrostructure, microstructure evolutions, tensile strength, microhardness tests were carried out to assess the welding properties of dissimilar steel and aluminum welded joints. The highest tensile strength of 240 MPa with the joint efficiency of 85% of the base metal was obtained when the parameters were set to tool rotational speed of 710 rpm, traverse speed of 40 mm/min, tool tilt angle of 0.5° and tool pin offset of 1.3 mm using a tungsten carbide tool. The highest microhardness of 246 HV was obtained in the stir zone. Scanning electron microscopy was used to study the joint interface structure. The presence of Fe5Al8 and FeAl intermetallic compounds was confirmed by energy-dispersive X-ray and X-ray diffraction analysis.

Microstructural evolution and mechanical properties of friction stir-welded C71000 copper–nickel alloy and 304 austenitic stainless steel

Dissimilar joints comprised of copper–nickel and steel alloys are a challenge for manufacturers in modern industries, as these metals are not thermomechanically or chemically well matched. The present study investigated the effects of tool rotational speed and linear speed on the microstructure and mechanical properties of friction stir-welded C71000 copper–nickel and 340 stainless steel alloys using a tungsten carbide tool with a cylindrical pin. The results indicated that a rotational-to-linear speed ratio of 12.5 r/mm did not cause any macro defects, whereas some tunneling defects and longitudinal cracks were found at other ratios that were lower and higher. Furthermore, chromium carbide was formed on the grain boundaries of the 304 stainless steel near the shoulder zone and inside the joint zone, directing carbon and chromium penetration toward the grain boundaries. Tensile strength and elongation percentages were 84% and 65% of the corresponding values in the copper–nickel base metal, respectively.

T-SAW methodology for parametric evaluation of surface integrity aspects in AlMg3 (AA5754) alloy: Comparison with T-TOPSIS methodology

The authors have proposed a novel Taguchi based Simple Additive Weighting (T-SAW) methodology in this study and investigated its comparison with Taguchi based TOPSIS (T-TOPSIS) methodology for responding towards its validity. The aforesaid two methodologies are implicated for examining turning operations on AlMg3 (AA5754) alloy in CNC Lathe machine using tungsten carbide tool, which are simultaneously implicated under sole manufacturing case for defining metrological comparison, for generating robust decision and for examining the validity of the novel T-SAW methodology. The authors found that both methodologies are imparting analogous parametric conditions i.e. cutting speed at 69.1 m/min, feed at 43 mm/min and depth of cut at 1 mm. Additionally, both methodologies are suggesting depth of cut as most significant and feed as least significant cutting parameter with 65.22% of contribution of depth of cut is reflected by T-SAW and 65.35% of contribution of depth of cut is reflected by T-TOPSIS methodology. It is found that the execution of proposed T-SAW methodology is simple as compared to other Taguchi based MCDM (Multi Criteria Decision Making) techniques and fluently defines effective parametric setting to be implicated under numerous manufacturing processes. An easy executable Multi Objective Optimization (MOO) framework is presented, Multi Response Performance Indicator (MRPI) is generated, parametric optimization of surface integrity aspects i.e. metal removal rate and surface roughness is presented, technical features for modeling T-SAW and T-TOPSIS methodologies are illustrated and the importance of cutting parameters for achieving output parameters is discussed in this study for cataloging rationalized experiments.

Substitution of commercially coated tungsten carbide tools in dry cylindrical turning process by HiPIMS coated niobium carbide cutting inserts

The deposition of a thin film tool coating as wear resistant layer on tungsten carbide (WC) cutting tool material marks the industrial standard for machining of various workpiece materials. Recent developments on alternative cutting materials show the potential of niobium carbide (NbC) for machining of iron-based materials and its use in cutting tool applications. In this study the tool behavior of two NbC substrates, defined as NbC0.88-12Co and NbC1.0-12Ni4Mo4VC respectively, is compared to commercial, submicron grained WC-6Co tool material. The wear performance of uncoated and physical vapor depositioned (PVD) coated cutting tools is analyzed by scanning electron microscope (SEM), electron backscatter diffraction (EBSD) and energy-dispersive x-ray spectroscopy (EDS) during adhesion tests and machining trials of carbon steel C45E. In uncoated condition, NbC1.0-12No4Mo4VC shows an average increase of material removal VW by 3% combined with a lower crater wear depth KT by 32% compared to industrial WC-6Co standard. Although microstructural defects are evident in NbC substrates, a similar tool performance of coated NbC cutting tools attests the successful substitution of WC-6Co cutting tool material for industrial machining processes.

Acoustic Emission-Based Tool Condition Classification in a Precision High-Speed Machining of Titanium Alloy: A Machine Learning Approach

Mechanical and chemical properties of titanium alloy have led to its wide range of applications in aerospace and biomedical industries. The heat generation and its transfer from the cutting zone are critical in machining of titanium alloys. The process of transferring heat from the primary cutting zone is difficult due to poor thermal conductivity of titanium alloy, and it will lead to rapid tool wear and poor surface finish. An effective tool monitoring system is essential to predict such variations during machining process. In this study, using a high-speed precision mill, experiments are conducted under optimum cutting conditions with an objective of maximizing the life of tungsten carbide tool. Tool wear profile is established and tool conditions are arrived on the basis of the surface roughness. Acoustic emission (AE) signals are captured using an AE sensor during machining of titanium alloy. Statistical features are extracted in time and frequency domain. Features that contain rich information about the tool conditions are selected using J48 decision tree (DT) algorithm. Tool condition classification abilities of DT and support vector machines are studied in time and frequency domains.

Influence of coconut oil on tribological behavior of carbide cutting tool insert during turning operation

In manufacturing industries, machining is considered as one of the most significant and effective processes. During machining process, cutting zone experiences the higher temperature due to friction between the chip-tool and work-tool interfaces, which directly influences the tool wear, surface quality and dimensional accuracy of the work material. Even though cutting lubricants are extensively used for lubricating and cooling the tool-workpiece contact area, their application has several drastic effects on environment and the health of operators. Hence, there is a need to identify an environmental friendly and user-friendly alternative to conventional cutting lubricants. The main objective of this work is to evaluate the effect of cutting lubricants on tool wear, friction coefficient, surface quality and chip morphology during turning of AISI 1040 steel with tungsten carbide tool insert under dry, wet, coconut oil, minimum quantity lubrication (MQL) using water-miscible fluid and MQL using coconut oil cutting conditions. The wettability characteristic of coconut oil on a carbide tool insert results in good adsorption on tool and workpiece, which causes effective lubrication and reduction in friction. It was found that the wettability angle of coconut oil is 33.7°, which greatly enhanced the wettability characteristics compared to the conventional cutting fluids. The MQL method using coconut oil machining condition resulted in a significant decrease in tool wear, friction coefficient along with favorable chip morphology and better surface quality of the workpiece.

Cutting forces and chip formation revisited based on orthogonal cutting of Scots pine

Abstract The objective of this study was to understand better the cutting forces and chip formation of Scots pine (Pinus sylvestris L.) with different moisture contents (MCs) and machined in different cutting directions. To that end, an orthogonal cutting experiment was designed, in which Scots pine was intermittently machined using a tungsten carbide tool to produce chips. The cutting forces were measured and the chip shapes were quantitatively described. Four conclusions can be drawn: (1) with increasing MC, the average cutting forces initially decreased and then stabilized, while the angle between the direction of the main and the resultant force continuously decreased. (2) The average cutting forces in the 90°–0° cutting direction were lower than the same forces in the 90°–90° cutting direction. (3) During machining, the dynamic cutting forces fluctuated less in the 90°–0° case. However, the dynamic feeding forces showed a decreasing trend in both the 90°–0° and the 90°–90° cases. (4) The process applied produced granule chips and flow chips, while less curly flow chips with a higher radius of curvature were more easily produced from samples with high MCs in the 90°–0° cutting direction.