Front case incombustion chamber, it’s a thin walled ring piece with poor rigidity and largematerial removal rate is prone to deformation. There arepositioning side assembled as locating and connecting role, also precision locatinghole and screw connecting hole alongside. External surface have various kind ofbosses, holes and grooves with different function. With high dimensionprecision, strict technical requirements, the case internal structure iscomplex with narrowed ring groove area, small space for tools operation; thinwalled components ring part and uneven thickness. All of above factors lead topoor stability and rigidity of the case parts operation, also worse radialdeformation resistance.

Components materials ishigh-temperature alloy Inconel 718, with the features of high hardness, highstrength, high-temperature resistance and difficult-to-cut. Under high cuttingtemperature, tools generate rapidly diffusive wear and severe work-hardening. Thus,cutting operation becomes more difficult with large cutting force in operationand usually up to two to three times more than that of steel. Low heatconductivity coefficient and poor thermal conductivity make heat intensivelyaccumulated around the tool nose and generates high heat in operation.

Machining process is as follow：

External rough turning of small face——Internal roughturning of large face—— Large face basis Turning ——Rough and finish turning ofsmall face——Internal finish turning of large face ——External ring groovesmilling——External boss profile milling——Face milling of external boss——Externalboss profile clearance milling——Inner-wall ring grooves milling——Milling ofRing grooves on inner-wall for large face(1)——Milling of Ring grooves oninner-wall for large face(2)—— Clearance milling of inner-wall ring groovesprofile for large face——Finish milling of inner-wall T grooves for largeface——Basis finish turning——Large face finish

blank                                                                                                   finished product（ red part）

Blank is forging pieces, after roughing it becomespreliminarily model, blank get rid of 50% material removal turn into finishedproducts. Complex structure with thin walled components feature, deformation inoperation will bring difficulty in machining. In tool selection, inserts withsharp edges geometry should be the first choice due to its capability of lowercutting resistance and deformation.

External rough turning of small face

Machining features: Roughing operationwith high allowance removal rate and has high machining efficiency requirementas well

Machines: CNC verticallathe

Tool selection principles: with relatively simple contour structure

inroughing, machining efficiency should be the emphasis in

operation. Ceramictools are the first choice, ZCC.CT tools has

obtained successful experiences inaerospace industry,

RCGN\RNGN round inserts series can dramatically increase

efficiencywith combination of CA1000.

Insert with positive angle inexternal turning：CRSCR3232P09（CA1000/ RCGN090700T01015-V）

Insert with negative angle in faceturning：CRDNN3232P12（CA1000/ RNGN120400T02020）

Cutting data：V=200m/min，fr=0.25mm/r

Internal rough turning of largeface

Machining features: Roughing operation with highallowance removal rate and has high machining efficiency requirement as well

Machines: CNC vertical lathe

Tool selection principles: With the same tool in thisprocess and the former one, it is able to complete external turning andinternal cavity with the help of positive ceramic

Tool：CRSCR3232P09

Insert：CA1000/ RCGN090700T01015-V

Cutting data：V=200m/min，fr=0.2mm/r

Large face basis turning

Machining features: base-levelturning

Machines: CNC vertical lathe

Toolselection principles: For High-temperature finishing, thin walled componentsneed for sharp geometry to lower cutting force, high indexing accuracy andrepeatability, safe and fasten clamping system of tool holder. The NF geometryof ZCC.CT is suitable for high-temperature thin walled alloy finishing, 55 ° Dshape insert can secure high insert nose strength, also possess sharpnessgeometry and precision ground of locating surface to improve indexing repeatability.M type clamping system ensures safety and fastens champing. Choosing gradeYBG105 as its excellent wear-resistance can improve tool life

Tool：MDJNR3232P15

Insert：YBG105/DNEG150608-NF

tool：MDJNL3232P15

insert：YBG105/DNEG150608-NF

Cutting data：V=40m/min，fr=0.15mm/r

Rough and finish turning of smallface

Machining features: Big face finish turning is applied tolocate machining of internal and external cavity of small face. It has complexstructure and involving special grooves requiring non-standard tools design,thin wall generate large cutting resistance

Machines: CNC vertical lathe

Toolselection principles: Grooving use square head in roughing operation, roundhead for finishing, tools for internal special groove are tailor-made, toolsfor external grooving is standard, sharp geometry is applied in finish turning.Insert ZIMF suitable for high-temperature alloy rough grooving, ZIGQ is appliedin finish profiling, tool holders for internal special groove are tailor-made,tool holders for external grooving is standard. NF-geometry is recommended asits sharp geometry, with M type clamping method. Choosing grade YBG105 as itsexcellent wear-resistance can improve tool life.

grooves in internal surface：QEKS3232R12-6N（YBG105/ZIMF608N-NM/ZIGQ6N-NM）

grooves in external surface：QEGS3232R12-4N（YBG105/ZIMF406N-NM/ZIGQ4N-NM）

special grooves in internal cavity face: special tool 1（YBG105/ZIMF304N-NM/ZIGQ3N-NM）

special grooves in internalcavity face: special tool 2（YBG105/ ZIMF304N-NM/ZIGQ3N-NM）

special grooves in internalcavity face: special tool 3（YBG105/ZIMF608N-NM/ZIGQ6N-NM）

Cutting data： Cutting data: Square head for roughing：V=40m/min，fr=0.25mm/r

Roundhead for profiling：V=50m/min，fr=0.15mm/r

Inner cavity：MDJNL3232P15（YBG105/DNEG150608-NF）

Basis：MDJNR3232P15（YBG105/DNEG150608-NF）

Cutting data:：V=50m/min，fr=0.15mm/r

Internalfinish turning of large face

Machining features: internal and external cavity, basisturning, the thickness of thinnest part reached 3.5mm only, severe deformationin machining

Machines: CNC vertical lathe

Tool selection principles: Inserts for finishing ofhigh-temperature alloy, high indexing accuracy and repeatability, thin-walledcomponents need sharp geometry to lower cutting force, ensures safety andfasten of toolchamping.correspondent product series: NF standard turning geometry suitable forhigh-temperature alloy thin-walled pieces machining, due to angle restriction,35°V shape insert demonstrates strong universality, and precision ground oflocating surface to improve indexing accuracy and repeatability. M typeclamping system ensures safety and fastens champing. Choosing grade YBG105 as itsexcellent wear-resistance can improve tool life.

Tool：MVJNR3232P16（YBG105/VNEG160408-NF）

Tool：MVJNL3232P16（YBG105/VNEG160408-NF）

Cutting data：V=50m/min，fr=0.15mm/r

External ring grooves milling:

Machining features: larger dimension ofring grooves

Machines:three-axial milling machine

Toolselection principles: High efficiency is required. According to the features ofcomponents structure and angle restriction tailor-made side and face millingcutter is designed. MPHT series insert is suitable for machining of grooves onplane surface, while CNE544R08-2 is suitable for machining of groove on slope.Under these two situations, YBG205 is the recommended grade

Straight：SMPX-160-B40-MP08-14（YBG205/MPHT080305-DM）

Slope：SMPX-160X25-B40-CNE544-16（YBG205/CNE544R08-2）

Cutting data：V=50m/min，fz=0.15mm/z

Profilemilling of external boss

Machining features: small gap in bossand small depth of cutting

Machines: Five-axial millingmachine

Tool selection principles: Due tonarrowed space for machining

choosing plunge milling by endmills with smalldiameter can

improve efficiency. XMR01 tool with straight shank is suitable

forthis situation.

Tool：XMR01-020-G20-WP05-02-M

Insert：YBG205/ WPGT050315ZSR

Cuttingdata：V=80m/min，fz=0.12mm/z

Face milling of external boss:

Machining features: face millingwith small working allowance

Machines: five-axial milling machine

Tool selection principles: high-temperature alloy millingshould focus on machining efficiency and cost. FMA01/FMA02 series mounted SEETinsert, high-feed milling series, are both can be applied in high-temperaturealloy machining. Selecting proper tool according to boss profile diameter, YBG205is recommended grade.

Tool：XMR01-063-A22-WP08-04

Insert：YBG205/WPGT080615ZSR

Cutting data：V=80m/min，fz=0.15mm/z

yellow area is the machiningpart

External boss profile clearance milling

Machines : five-axial millingmachine

Tool selection principles: solid carbide endmills forhigh temperature, GM ball-nose solid carbide endmill can processhigh-temperature alloy with stable performance, ZCC.CT offers specific tool accordingto component’s corner radius.

Tool：PM-2B-R3.0

Cutting data Cuttingdata：V=30m/min，fz=0.06mm/z

Inner-wall ring grooves milling

Machining features: Ring grooves on face with large circle size.

Machines: three-axial milling machine

Toolselection principles: It is the critical to improve milling efficiency andreduce cost, with a same tool is able to machine external ring grooves on slopeface.

Tool：SMPX-160-B40-MP08-14

Insert：YBG205/MPHT080305-DM

Cutting data：V=50m/min，fz=0.15mm/z

Milling of ring grooves on inner-wall for large face (1)

Machining Features: Ring grooveon slope with large circle size.

Machines: three-axial millingmachine

Tool selection principles: It is the critical to improvemilling efficiency and reduce cost, with a same tool is able to machineexternal ring grooves on slope face.

Tool：SMPX-160X25-B40-CNE544-16

Insert：YBG205/CNE544R08-2

Cutting data：V=50m/min，fz=0.15mm/z

Milling ofring grooves on inner-wall for large face (2)

Machining Features: Parts of circle size is small cannotbe machined by side and face milling cutter

Machines: Five-axialmachine center or three-axial milling machine.

Tool selection principles: FMR01 series tool holder,mounted with RCKT round insert, it is suitable for machining of material withthis structure and improve milling efficiency.

Tool：FMR01-032-XP25-RC10-02

Insert：YBG302/RCKT10T3MO-DM

Cutting data：V=50m/min，fz=0.15mm/z

yellow area is the machining part

Clearancemilling of inner-wall ring grooves profile for large face

Machines: Five-axial machinecenter or three-axial milling

Tool selection principles: With A same tool is able tomachine external boss profile clearance.

Tool：PM-2B-R3.0

Cutting data：V=30m/min，fz=0.06mm/z

Finish Milling of inner-wall T groovesfor large face

Machining features: Sphericalsurface grooves

Machines: Five-axial machine center or three-axialmilling

Tool selection principles: ball-nose milling cutter issuitable for spherical surface machining. ZCC.CT BMR04 tool, mounted with ZOHX seriesinsert through fully ground process, it can achieve high precision. Also,ZOHX3207-GF geometry is capable of finish milling in combination with gradeYBG205 due to its sharp edge and high strength.

Tool：BMR04-032-G32-M

Insert：YBG252/ZOHX3207-GF

Cutting data：V=40m/min，fz=0.1mm/z

Machining features: Turning base-level, thinnest partonly 3.5mm, severe deformation

Machines: CNC vertical lathe

Toolselection principles: inserts for finishing of high-temperature alloyThin-walled components require sharp geometry to reduce cutting force, highindexing accuracy and repeatability. Safety and fasten Tool holder champing. 55° D type insert can ensure high insert nose strength; also possess sharpnessgeometry and precision ground of locating surface to improve indexing accuracyand repeatability. M type clamping system ensures safety and fastens champing.Choosing ZIGQ3N-NM dedicated geometry with grade YBG105, it is suitable forspecial conditions machining thanks to its excellent wear-resistance and longertool life.

Tool：MDJNL3232P15

Insert：YBG105/DNEG150608-NF

異型刀桿2（YBG105/ZIGQ3N-NM）

Cutting data：V=40m/min，fr=0.15mm/r

Machiningfeatures: Turning base-level, thinnest part only

3.5mm, severe deformation.

Machines: CNC vertical lathe

Tool selection principles: inserts for finishing of high

temperature alloyThin-walled components require sharp

geometry to lower cutting force, highindexing accuracy and

repeatability. Safety and fasten Tool holder champing. 35° V

type insert can ensure high insert nose strength; also possess

sharpnessgeometry and precision ground of locating surface

to improve indexing accuracyand repeatability. M type

clamping system ensures safety and fastens

champing.Choosing ZIGQ3N-NM dedicated geometry with

grade YBG105, it is suitable forspecial conditions machining

thanks to its excellent wear-resistance and longertool life.

Tool：MVJNR3232P16

Insert：YBG105/VNEG160408-NF

Tool：MVJNL3232P16

Insert：YBG105/VNEG160408-NF

Cutting data：V=50m/min，fr=0.15mm/r