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
