Sandvik-coromant Machining carbon fibre materials User Manual

Machining carbon bre materialsUSER’S GUIDE

Epoxy • The high-quality standardPhenolic • Fire resistantBMI, cyanate • High temperaturePolyester, Vinylester • Low costTh

Unidirectional reinforcement (UD), in which maximum •strength and stiffness are obtained in the direction of the ber Properties: - highest s

Machining compositesFRPs are not homogeneous, therefore •several aspects affect their machinability: Continuous Fiber• Continuous ber can be

Common production methodsPrepregs• - Fibres and resin come together as a “tacky” fabric - Are stacked up by hand Injection• - The

Additional featuresGlass cloth - • UV protection, paint preparationGelcoat - • For surface nish, corrosion protectionLightning s

How to identify a materialVisual inspection:• - can help to identify some features of the materialGeometrySurfaceResinFibresThickness•Ap

How to identify a materialGeometrySurfaceResinFibresGeometry can suggest the application• - Thick component: primary structure - Thin compo

Surface featuresResinFibresGlass cloth• - a layer of white glassbre - glassbre layers can possibly generate break out problems suc

Resin identicationResinSurfaceFibresColourEpoxy resins• - amber-brownish Thermoplastics• - in some cases blueShiny• - Therm

FibresSurfaceResinGeometryColourCarbon bres• - black Glass bres• - whiteAramid bres• - yellowFabricUnidirectional• Wo

ContentGENERAL COMPOSITE AREA INFO MATERIAL AND COMPONENTS INFO HOLE AND SURFACE QUALITY MACHINING STRATEGIES AND MACHINES APPLICATIONS PRODUCT O

StacksFRPs are often used in stacks with aluminium or titanium• - primary structural components - oor panels, for fastening Typical c

Health & SafetyWhen machining, dust extraction is strongly •required - For the operator safety - For the machine maintenance: carbon dus

HOLE AND SURFACE QUALITYSANDVIK COROMANT USER’S GUIDE - COMPOSITE SOLUTIONS 22

Quality issues in CFRPQuality is not easily assessed:• - there is no chip to look at - roughness measurement is not signicant - damage

In composite materials, there can be loss of hole •quality long before tool failureTherefore, the hole quality determines when the tool •needs to be

Hole requirements Stacked materialsCommon demands• - Cpk>1,33 - Ra<3,2 in carbon bre - Ra<1,6 for Aluminium and titanium

Increasing productivityIncreased feed and speed will improve productivity, but •another more critical factor is hole quality. Poor hole quality m

MACHINING STRATEGIES AND MACHINESSANDVIK COROMANT USER’S GUIDE - COMPOSITE SOLUTIONS 27

Machining mechanismComposites: • brittle fracture The bres are shattered and cut• - The force needed is much lower - The tool toughnes

Machining strategiesCFRP• - Quality must be checked both at hole entry and exit: different cutting conditions may be needed. - Quali

GENERAL COMPOSITE AREA INFOSANDVIK COROMANT USER’S GUIDE - COMPOSITE SOLUTIONS 3

Peck cycle metalic structureBegin CycleBegin cycle at fast approachlevel (FAL). Typically 2.5mmabove material.Drill CFRP until the drill point is 0.5m

Machining strategiesTop and bottom surface are often different, hole quality •can therefore depend on where the drill enters or exits. A coa

Machine types CNC and PKM (Parallel Kinematic Machines)Facts• - CNC controlled - Stable environment - Short tool overhang - High an

Machine typesRobots Facts• - CNC controlled - Flexible solution - Short tool overhang - Holemaking primary focus - CFRP or st

Machine typesPower feed machinesFacts• - Electrical or pneumatic versions - Holemaking applications - Machinel adapted tooling -

Machine typesPower feed and hand toolsFacts• - Electrical or pneumatic versions - Holemaking - Machinel adapted tooling - Low rpm

APPLICATIONSSANDVIK COROMANT USER’S GUIDE - COMPOSITE SOLUTIONS 36

Typical component featuresHolemaking• Edging• Trimming• Faces• Holemaking in carbon breHolemaking in carbon bre, aluminium and tita

Application exampleHolemaking in CFRPFacts and demands:• - Fibre rich carbon bre - Unidirectional - Minimal splintering of bres -

Application exampleHolemaking in CFRPFacts and demands:• - Resin rich material - Electrical or pneumatic versions - Minimal delamination

Carbon bre is being utilized at a greater •scale which is increasing the demands on automated production to improve productivity. Carbon ber can be

Application exampleHolemaking in CFRP/AL stackFacts and demands:• - Carbon bre and aluminium stack - Minimal splintering of bres -

Application exampleHolemaking in CFRP/Ti stackFacts and demands:• - Carbon bre and titanium stack - Reduced burr on exit - Good surfac

Application exampleHolemaking: hand drilling in CFRPFacts and demands:• - Carbon bre - Reduced burr on exit - Good surface nish and

Application exampleHolemaking: hand drilling in CFRP/AL and CFRP/Ti stackFacts and demands:• - Carbon bre and metal stacks - Reduced burr

Application exampleEdging of carbon breFacts and demands:• - Primary structure carbon bre - High material removal rates - Minimal sp

Application exampleSturtz milling: proling of carbon breFacts and demands:• - Tilting of tool 2-10 degrees - High rpm and feed rate

Ball end scanning Vs Sturtz 32mm diameter tools used with the same cutting data.• Typical to use smaller ball end tools resulting in even •great

Application exampleSurface machining of carbon breFacts and demands:• - Primary structure carbon bre - Minimal splintering of bres and de

Application exampleEdging of carbon breFacts and demands:• - Carbon bre skin - Minimal splintering - Good surface: Ra value of 1.2

PRODUCT OFFERSANDVIK COROMANT USER’S GUIDE - COMPOSITE SOLUTIONS 49

Composites and especially carbon •bre are being utilized at a greater extent due to its benetial properties. Driving forces taking advantage of •

Product solutionsHand drillHand drillHand drillPower feedPower feedCNC machineCNC machineCNC machineCNC machineDrillingDrillingChamferCFRPCFRP/AL/TiCF

Product solutionsStandard products• Holemaking - CoroDrill 854 and 856 composite geometries Milling - CoroMill Century and CoroMi

Product offer drillingCNC – automated machineCFRP• - Fibre rich material CoroDrill 854 Carbide / PCD - Allround geometry Co

Product offer drillingPower feed machineCFRP• - Fibre rich material CoroDrill 854 Carbide* / PCD - Allround geometry CoroDr

Product offer drillingHand toolCFRP• - Fibre rich material PHT geometry Carbide* CFRP/Aluminium/• Titanium - C

Product offer edging/slotting CNC – automated machineCFRP• - Carbon bre CoroMill Plura Carbide* - Carbon bre CoroMill P

Product offer edging/slotting CNC – automated machineCFRP• - Carbon bre CoroMill 590 PCD - Carbon bre CoroMill 390 P

CoroDrill grades Grade comparisonN20C, Solid Carbide with • Diamond coating - Low friction coefcient - Stable hole dimensions

Geometry selection guidelinesMaterial usage & curing temperatureCFRPMaterialPrimary- (medium-high T epoxy) - Low temperature Epoxy- Non structur

Geometry selection guidelinesCFRP stacked materialMaterialAluminium stackTitanium stackTi/AL stack CD 854 X - - 86PT*(for power feed a

Benets from composite materials are •especially important where weight control is critical: Aerospace industry (main focus) - New aeroplane mode

SOLUTION/PROBLEM SOLVINGSANDVIK COROMANT USER’S GUIDE - COMPOSITE SOLUTIONS 60

Cutting dataTipycally: • - speed 60-120 m/min - feed rate 0.02-0.15 mm/rev PCD allows for higher feed and sometimes speed•With pos

Machining strategiesProblemSolutionDelaminationSplinteringPoor tool lifePoor quality on a coated materialDisparity of quality on entry and exitReduce

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MATERIAL AND COMPONENTS INFOSANDVIK COROMANT USER’S GUIDE - COMPOSITE SOLUTIONS 7

Denition: engineered materials made from two or more constituent materials with signicantly different physical or chemical properties which remain s

Carbon bres are characterised by:• - High strength difcult to cut - High elastic modulus abrasive Can be in unidirectional tapes