imachining for Super Alloys & Hard Materials Amod Onkar SolidCAM Ltd.

Transcription

1 imachining for Super Alloys & Hard Materials Amod Onkar SolidCAM Ltd.

2 Hard Materials & Difficult to Cut Materials Titanium Inconel Stainless Steel Stellite Hastelloy Tungsten Prehardened Tool Steel (>45 HRC)

3 Challenges in Machining Hard Materials Chip thickness variation High heat Stress High tool wear Edge build up Low thermal conductivity Deformation process changes during machining Getting the right cutting conditions

4 Machining Influencers CNC Machine Cutting Tool Fixture CAM toolpath Coolant

5 SolidCAM imachining Ultimate Solution for Hard Material Machining

6 imachining The revolution in CNC Machining Increased productivity due to shorter cycles time savings 70% and more! Dramatically increased tool life Unmatched hard material machining Outstanding small tool performance 4-Axis and Mill-Turn imachining High programming productivity Shortest learning curve in the Industry imachining Wizard + imachiningtoolpath = The Ultimate Solution! The unique Technology Wizard provides optimal feeds and speeds, taking into account the toolpath, stock and tool material as well as machine specifications.

7 imachining 3D Utilizing Proven imachining 2D & Technology Wizard Algorithms Used both for 3D surfaced and prismatic parts. Optimized machining of each Z-Step, using proven imachining 2D technology Deep roughing uses the whole length of the flute, shortening cycle time and increasing tool life Rest material machining in small upward steps, optimized for constant scallop height, further shortens cycle time Intelligent localized machining and optimal ordering eliminates almost all long positioning moves and retracts A dynamically updated 3D stock model eliminates air cutting Tool path automatically adjusts to avoid contact between the holder and updated stock Combined with HSM Finish, imachining 3D provides a complete machining solution for 3D parts.

8 imachining Two Components imachiningtoolpath + imachining Wizard = The Ultimate Solution! + >> More info

9 Standard Offset Tool paths With traditional fixed "step-over" offset tool path, the cutting tool "steps over" a fixed amount to cut the next row of material - this creates areas where the tool is subjected to heavy forces, especially in tight corners. CNC operators had to slow down the cutting operations and take very shallow cuts to minimize cutting tool breakage and wear in these high stress areas. The slow speed of the cut and the shallow depth of the cutter, are set for the entire process - so the impact of even just a few problematic areas could severely slow the entire process down and cause high rates of tool wear. This also greatly lessens cutter life as only a small percentage of the bottom of the cutter is used during shallow cuts.

10 imachining s Intelligent Tool Path Smooth Tangent Tool Paths (Smooth Machining) Controlled Step Overs (no over loading the tool) Exact Stock Machining (no air cutting)

11 imachining Features Unique Toolpath Pattern Optimum automatic Cutting Conditions Constant Cutting Force Vibration Control

12 imachining - Solomon s Theory First definition of HSM was proposed by Carl Solomon in 1931 He assumed that at certain cutting speed which is approximately 5-10 times higher than conventional machining, the chip tool interference temperature will start to decrease

13 imachining Transition & HSM Range

14 High Speed Milling temperature balancing process Temperature Rises Transition to plastic phase Cutting force reduced Less energy expended Less Heat Produced Temperature goes down This sensitive sequence maintains a stable cutting temperature, due to its negative feedback, and therefore maintains stable high speed cutting The stable high speed cutting is very prone to disruption if any of the influencing factors changes for some reason e.g. the air stream is temporarily blocked the temperature rises uncontrollably and the tool breaks This sensitivity of the temperature balancing process demands that to avoid collapse of the high speed cutting, a number of parameters have to be strictly controlled at their nominal constant values

15 imachining Intelligent Tool path Manage Cutting Angle First, imachining intelligent tool paths manage the cutting angle (section of tool engaged with the stock material). When the cutting angle is properly controlled throughout the entire cut, the result minimizes the forces on the tool, allowing the tool to cut much deeper without excessive wear or breakage. Deeper cuts, using all of the cutting tool length, require far fewer passes, greatly reducing the cycle time of the part. Also, since the entire cutting tool length is used, tools are no longer replaced with only a small percentage of the bottom of the cutting tool used - Cutting Tool life dramatically increases to many times that of a cutting tool used in a Traditional tool path. Another major benefit is the ability to use small cutting tools, even for really hard materials

16 imachining Intelligent Tool paths Manage the Feed Rate Second, imachining Intelligent Tool Paths manage the "Feed Rate In imachining, since the Cutting angle maybe constantly changing (morphing Spiral), the Feed Rate is adjusted in a manner that keeps a constant Chip Thickness. This reduces or eliminates the uneven loading forces on the tool, that significantly reduce the life of the Cutting Tool - by having a constant and reduced load on the tool, tool life is greatly increased.

17 Peripherals that influence HRSA Machining Cooling Cooling Fluid or Air Cooling Design Cutting Tool Cutting Tool Sharp Corner/Chamfer/Corner Radius Tool Holding Collet / HydroGrip / Power Chuck Work Holding Work Holding Mechanical Vice / Hydraulic Vice/ Holding Fixture

18 Cooling Cooling plays a Pivotal role in machining HRSA Materials High pressure (>40 Bar) Fluid cooling must be used for HSRA Materials High pressure Air must be used for Steel (45 HRC & beyond) Ring Cooling Design for HRSA Materials

19 Cutting Tool Use a cutting tool with maximum core diameter (Reduces Deflection) Use a cutting tool with Corner radius (Sharp Corner increases chipping) Use a Honed tool as it helps extend tool life considerably Tool Chipping Comparison Courtesy Sandvik Ltd.

20 Tool Holding Use of Hydrogrip / Shrink Fit / Power Chuck gives following benefits Minimized runout which increases tool life Cutting Stability allowing for greater depth of cut High Clamping forces which prevent pull out of high helix cutters For every 10 microns in added run out the tool life reduces by 50%!

21 Feed Rate Control Peripheral & Center When programming with the feed applied to the tool centre, the feed must be reduced when producing an internal radius or a circular motion (G2 or G3) if not using radius compensation. This is done since the periphery has to travel further than the tool centre for the same angular rotation. Slider at 100% means imachining will maintain a constant Chip Thickness when cutting in corners. Slider at 0% means imachining will maintain a constant Feed rate between cutting G1 (Straight line) & Corner (G2) Slider must be at 100% for Super Alloys

22 Effect of Moat Width The following 3 images demonstrate the moat width with different tools in a slot of 25 mm Width Slot Machined by 16 Dia End Mill Slot Machined by 12 Dia End Mill Slot Machined by 10 Dia End Mill The toolpath with minimum movement while moating would wear the tool very fast

23 Machinability of a Material

24 What is Machinability? Machinability is a term indicating how the work material responds to the cutting process. In the most general case good machinability means that material is cut with good surface finish, long tool life, low force and power requirements, and low cost. Several definitions of Machinability is available, but in practice so called machinability index is often quoted Km = V 60 / V 60R Km V 60 V 60R = Machinability Index = Cutting speed for the target material that ensures tool life of 60 minutes = Cutting speed of Reference material that ensures tool life of 60 minutes Km > 1 machinability of the target material is better than that of the reference material, and vice versa.

25 Sample Calculation of Machinability The reference material for steels, AISI 1112 steel has an index of 1 Machining of this steel at cutting speed of 0.5 m/s gives tool life of 60 min Therefore, V 60R = 0.5 m/s The machinability index for SS 302 is Km = 0.23/0.5 = 0.46 (Tool life of 60 min for 302 SS is reached for cutting at 0.23 m/s) The machinability index for AISI 1045 is Km = 0.36/0.5 = 0.72 (Tool life of 60 min for AISI 1045 is reached for cutting at 0.36 m/s) So the machinability order would be: AISI 1112 > AISI 1045 > 302 SS

26 Why is Machinability Important? Improves tool life dramatically Allows imachining to decide on exact cutting conditions Better Surface Quality Reduces the chances of warpage Improves overall process

27 Factors Affecting Machinability in Real World Conditions Physical properties of the work material The basic nature brittleness or ductility etc. Microstructure Mechanical strength fracture or yield Hardness Hot strength and hot hardness Work hardenability Thermal conductivity Chemical reactivity Stickiness / Self lubricity Levels of the process parameters Cutting tool - Material and Geometry Machining environments (cutting fluid application, Work Holding etc.)

28 Measuring the Machinability of a Material Sample Part AISI 1045 Steel Machine Mazak FJV 10KW Spindle Part Size 100 X 75 X 50 Cutting Tool Dia 12 End Mill (4 Flute, 45 Deg Helix) Cutting Depth 24 MM

29 Measuring the Machinability of a Material Define a New Material with UTS taken from Test Chart or from

30 Define a 2D imachining toolpath at level 8 for the geometry shown. Ensure to get Whole Number ACP in order to prevent chatter Measuring the Machinability of a Material

31 Measuring the Machinability of a Material Note down the marked Values. Note that the Power is shown as 5.2 KW for this Cut.

32 Calculate the TP & Generate the GCODE Measuring the Machinability of a Material

33 Measuring the Machinability of a Material Once the machining starts observe the Spindle Load after 2 passes till the machining ends. Let s assume the load was 60% which translates to 6 KW on a 10 KW Spindle

34 Measuring the Machinability of a Material As per the UTS of the Material we should have had 52% load on the spindle. 60% load means the material is slightly tougher to machine.

35 Measuring the Machinability of a Material Edit the material database and reduce the machinability factor to about -16%

36 Measuring the Machinability of a Material Edit the toolpath and enter the noted values before the Machinability was modified. If we get the power as 6 KW, We have exactly determined the machinability of the material.

37 imachining Forces on Spindle & Axis

38 imachining Effect on Machine Tools The imachining Tool path, combined with optimum cutting conditions provided by the Technology Wizard, ensure constant load on the tool in any situation. imachining makes sure that the constant load on the tool will be such that the spindle load will range from 4% to 17% of the maximum possible spindle power load (depending on the LEVEL of the slider in imachining Wizard) Hermle company concluded that with imachining, the forces acting on the their Spindle are the smallest of all CAM systems using High Speed Machining. Makino company also tested imachining on its machines (MAKINO A55 & A61) and reached similar conclusions

39 imachining Cutting Force Measurement Cooperation of the University of Bohemia, Czech Republic & SolidCAM focused especially on cutting force measurement This University is equipped with several types of dynamometers: Rotational cutting force dynamometer Axial dynamometer for drilling operations Work piece dynamometer

40 Rotating Dynamometer Designed for cutting force measurement of all types of operations Possible measured forces/directions: Components Fx, Fy, Fz Torque moment Mz Position: Spindle

41 Axial Dynamometer Designed for cutting force measurement during drilling and turning operations Possible measured forces/directions: Components Fx, Fy, Fz Torque moment Mz Position: Machine table

42 Work Piece Dynamometer Designed for cutting force measurement of all types of operations Possible measured forces/directions: Components Fx, Fy, Fz Position: Machine table

43 Data Measurement Data is transferred by shielded wire PC is equipped by a measuring card Every component is processed separately Sampling: Hz SW: LabVIEW

44 Sample Part Closed pocket with an island Pocket depth 24mm Material: Aluminium_100BHN (100HB) End mill: Diameter (D)= 8mm Number of flutes = 3 A p = 30mm (cutting length) Ha = 38 imachining level: 5 (Moderate)

45 Conventional Pocketing Strategy Cutting Force Classical pocketing Feeds and speeds set according to the cutting tool manufacturer s catalogue A p = 4mm A e = 7,2mm f z = 0,09mm Yellow: Approach Green: Machining

46 imachining Cutting Force Feeds and speeds: According to SolidCAM - imachining database v c = 283 m/min (11250 rpm) v f = 4507 mm/min (fz = 0,13 mm/tooth) Yellow: Approach Green: Machining

47 Stainless Steel P660 & Titanium TiAl6V4 Trials - Kennametal Test Objective - Test Material - High Speed Machining of Titanium and SS By Using SolidCAM imachining generated Program with Kennametal Harvi 2 ER D12 and D16 x R3 end mill. Grade KCSM15 Z-6. Stainless Steel & Titanium Blocks supplied by Major Aerospace Company. Machining - Periphery and Pocket machining. Machine - Mazak FJV200 (12000 RPM,Spindle Power 15KW Continuous)

48 Stainless Steel P660 - Trials Stock Size 250 X 200 X 60

49 SS Periphery Milling Roughing 1.Cutter : Dia 16R3 bull nose DOC: 23mm Vc= 171 ( RPM 3395) Fz/tooth = at level 4. Finishing 2.Cutter : Dia 16R3 bull nose DOC: 23mm Vc= 205 ( RPM 4070) Fz/tooth = at level 6. Adapter Shrink fit withhsk63a backend Cycle time 3min 36sec

50 SS Pocket Machining Roughing 1.Cutter : Dia 16R3 bull nose DOC: 23mm Vc= 171 ( RPM 3395) Fz/tooth = at level 4. Finishing 2.Cutter : Dia 16R3 bull nose DOC: 23mm Vc= 205 ( RPM 4070) Fz/tooth = at level 6. Adapter Shrink fit withhsk63a backend Cycle time 4min 48sec

51 Titanium Machining Toolpath STOCK SIZE X 175 X 50

52 Titanium Periphery Machining Roughing 1.Cutter : Dia 16R3 bull nose DOC: 20mm Vc= 83 ( RPM 1857) Fz/tooth = at level 4 of SolidCAM Adapter Shrink fit withhsk63a backend Cycle time 3min 18sec

53 Titanium Pocket #1 Machining Roughing 1.Cutter : Dia 16R3 bull nose DOC: 20mm Vc= 83 ( RPM 1857) Fz/tooth = at level 4 of SolidCAM Adapter Shrink fit withhsk63a backend Cycle time 4min 42sec Spindle Load 20%

54 Titanium Pocket #2 Machining Roughing 1.Cutter : Dia 12R0.8 bull nose DOC: 17 mm Vc= 113 ( RPM 2997) Fz/tooth = at level 7. Finishing 2.Cutter : Dia 12 R0.8 bull nose Vc= 83 ( RPM 4070) Fz/tooth = at level 5. Adapter HP Chuck withhsk63a backend Cycle time 3min 58sec

55 Tool wear D12 on Titanium 20 X Magnification Upto 0.1 mm Wear Observed on all Cutting Edges

56 imachining Success Customer: NIV Haritot. Material: Titanium The customer had 75 pieces to produce Standard cutting time:17 min / Piece imachining 2D = 3.5 minutes / Piece Saving by imachining : 80% saving Total time saving for 75 parts : 16 hr 52 min

57 imachining - Inconel Component : Aerospace component Material : Inconel 718 Machine : Hurco VMX50 Tools used : Dia 16 Chatter Free End Mills Operation : imachining 3D roughing End Mill used : Chatter free end mill (Iscar Make) Dia of End mill : 16 Ap : 33 mm Ae : Vc : 81 m/min (Iscar 45 m/min) Feed/ tooth : Tool Life : 86 Mins (Iscar Estimate 26 mins)

58 imachining Success Stories Burns Machinery - US Material Inconel 625 Machining Time savings 75% Tool Life - > 300%

59 imachining Success Stories Kline Oil Field Equipment - US Material Inconel 625 Machining Time savings 86% Tool Life - > 500%

60 imachining Success Stories Roku Roku - Japan Material Tungsten Carbide (90 HRC) Competitor CAM 42 hours (9 Tools) imachining - 54 Minutes (1 Tool)

61 Thank You!!