Experimental Research on the Selection of Tool Material in Turning

Superalloy GH4169

Fengyun Yu1, a*, Yuan Tu1, b, He Wang1, c, Lin Wu1, d, Yunliang Fu1, e

1 Heilongjiang University of Science and Technology Harbin, 150027，China

ayufengyun179@sohu.com, btuyauna@163.com, c1059761358@qq.com

Keywords: Superalloy, Cutting force, Surface roughness, Tool wear

Abstract. Through machining superalloy GH4169 in center lathe by four kinds material of tool,

which are YT763, K313, KC5510 and SM1105, analyzing the changings of cutting force and

surface roughness in different material of tool and the forms of tool wear. As the experiment data

shows, there is little influence of the different tool in material with the same coating to cutting force

and surface roughness. KC5510 is more suitable for constant speed cutting GH4169, which offers

the choices of tool material when machining superalloy in common speed.

Instruction

Nickel base superalloy is one of the most produced and used superalloy in nation, which is widely

applied to the area of aero-engine manufacturing and the hot end components of gas turbines, such

as the blades in turbine, turbine vane, turbine disk and combustor etc. [1]. Due to its good working

performance in high temperature and stress environment, for instance, high working temperature,

stable weave, little harmful phase and good ability to antioxidant hot corrosion, it plays an

important role in superalloy [2]. However, superalloy is one of the most difficult materials to

machining, which machining with the features of larger cutting force, higher cutting temperature,

serious work hardening, larger plastic deformation, tool wear easily and the surface finish and

precision are difficult to assurance [3]. Therefore, for its natures, besides the base performance like

the common tool, it must be offered with higher heat resistance, hot impact resistance, well

mechanical property in high temperature and good reliability etc. in machining [4]. According to the

experiment research on the tool material of cutting superalloy in domestic and abroad, the tool

materials of cutting superalloy mainly have carbide, coated carbide, ceramic cutting tools and cubic

boron nitride cutting tools [5].

The experiment of cutting superalloy GH4169 with four different carbide cutting tools,

comparing to the changing law of cutting force, surface roughness and tool wear in different tool

material, finding the better tools material. Also, it provides the reference to the reasonable choices

of tools material in practice machining when cutting superalloy in center lathe.

Experimental designed

Experiment conditions. The material of work piece is superalloy GH4169, rod shape, the diameter

is 140mm, and the length is 300mm. The experiment machine is CA6140 lathe which maximum

rotate speed of spindle is 1400 r / min, and turning conditions is dry cutting. The experiment has

Materials Science Forum Vols. 800-801 (2014) pp 460-464Online available since 2014/Jul/28 at www.scientific.net© (2014) Trans Tech Publications, Switzerlanddoi:10.4028/www.scientific.net/MSF.800-801.460

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three carbide cutting tools. One is K313, type CNMG120404MS, uncoated. Another is KC5510,

type CNMG120404MS, PVD coating and the coating material is TiAlN. The last is SM1105, type

CNMG120404QM, PVD coating and the coating material is TiAlN. In addition, a carbide welding

cutter of YT763 was chosen. The experiment locale is shown in Figure 1.

In the experiment, the cutting force changes were measured by Kislter dynamometer. Using

Times TR100 pocket surface roughness measuring instrument to measure the machined surface

roughness. Measuring five points on machined surface, and averaged surface roughness values as

required for the experiment. Use Dino-Lite AM4113 microscopy to observe tool wear.

Cutting Parameters Selection

(1) Cutting Depth, ap

Rough machining gets lower surface roughness (Ra50～12.5µm), the desirability cutting depth

is 2 to 6mm. Cutting depth is chosen from 0.3 to 2mm in Semi-finishing(Ra6.3～3.2µm)and from

0.1 to 0.4mm in finishing(Ra1.6～0.8µm).

(2) Feed, f

Feed affects machining accuracy and surface roughness. The cutting force is not big due to a

small cutting depth in semi-finishing and finishing. Feed is primarily limited by surface roughness.

Feed is excessive or too little which will affect the accuracy of experimental results. Therefore, feed

is 0.1～0.24mm/r.

(3) Cutting speed, v

When cutting nickel-based super alloy, higher speed lead to accelerate tool wear and shorten tool

life. However the lower speed increases cutting force and is easy to cause tool tipping. Under the

premise of ensure tool life and combining the advantages of coated tools shall be chosen higher

cutting speed.

The experiments on the CA6140 lathe process parameters of finish machining are given,

including the feed rate 0.15mm/r and the depth of cutting 0.4 mm. Considering the relatively large

diameter of the work piece, so chose the spindle speed 160 r / min and the turning velocity is

67m/min.

Fig.1 Turning experiment locale

Materials Science Forum Vols. 800-801 461

Experimental results and analysis

Tool material impact on cutting forces. The cutting force variation curve of K313 material cutting

tool changing with time measured by Kislter dynamometer is shown in Figure 2. The carbide cutter

K313 is a kind of non-alloy WC / Co fine-grained material. It can be seen from the figure that the

variation of cutting forces in three direction Fx, Fy and Fz is quite big with the time, when cut

superalloy GH4169, especially the main cutting force Fz has the biggest variation. The cutting force

variations reflect the vibration of cutting tool during working. The cutting process is not smooth

when use K313, and the vibration of cutting tool is quite large which will accelerate the tool wear,

reduced tool life.

Fig. 2 Cutting force variation of K313 material tool with time

When the cutting speed "v" is 67m/min, cutting depth "ap" is 0.4 mm, feed rate "f" is 0.15 mm/r

and tool nose curvature radius "r" is 0.4mm,the cutting forces in three direction Fx, Fy and Fz with

different tool material are shown in table 1.

Table 1 Cutting forces of different tool material

Fool Material Fx Fy Fz

YT763 106.3 155.8 255.2

K313 113.3 108.0 253.7

SM1105 575.2 1034 547.2

KC5510 118.7 132.9 254.0

The curve of cutting force with different tool material is shown in Figure 3. It can be found that

the cutting forces of SM115 is much larger than the other three tool materials, but K313, YT763

and KC5510 don't have too much difference. It indicated that tool material don't have a noticeable

effect on cutting force at normal cutting speed.

Fig. 3 Cutting force of different tool material

462 High Speed Machining VI

The influence on surface roughness of tool materials. The surface roughness of different tool

materials is shown in Figure 4. It can be found that the uncoated cutting tool YT763 has the biggest

roughness value, because different geometric angle of whole weld cutting tool will affect the

surface roughness. Uncoated tool K313 has an approximately same angle with coated tools SM115

and KC5510, and the difference of roughness value is very small. It mains that the tools with or

without coating don't influence the roughness too much. The materials of tools that have the same

coating don't influence the roughness too much.

Fig. 4 Surface roughness of different tool materials

Different kinds of tool wear with different tool materials. The wear of uncoated tool K313 and

coated tool KC5510 are shown in Figure 5. It shows that the rake wear of the two tools are crater

wear, and K313 is worse. From the experiment, we can see that the wear of coated tool don't affect

the reuse, but uncoated tools have an obvious increasing of cutting force. Compare the flank wear

with each other; KC5510 is much better than K313.

(a) KC5510 rake wear (b) KC5510 flank wear

(c) K313 rake wear (d) K313 flank wear

Fig.5 Tool wears

Materials Science Forum Vols. 800-801 463

Tool material for superalloy material GH4169. When choosing the tool material, it is better to

use that the cutting force, surface roughness and tool wear are small based on their performances.

The analysis for the experimental results show that K313 and KC5510 are better than YT763 and

SM1105 in terms of cutting force; KC5510, K313, and SM1105 are better than YT763 in surface

roughness, so K313 and KC5510 will be selected initially. But the wear of K313 is worse, so the

conclusion is that the coated carbide cutting tool with KC5510 material is the most suitable choice

for CA6140 lathe when turning superalloy GH4169 at normal speed.

Conclusion

Through the superalloy GH4169 processed in center lathe with uncoated cutting tool YT763 and

K313, and coated cutting tool KC5510 and SM1105, analyzing the changings of cutting force and

surface roughness in different tool material, as well as the form of tool wear. Based on the

experiment analysis, there is little influence of the different tool in material with the same coating to

cutting force and surface roughness; While the uncoated cutting tool is more seriously than the

coated one on tool wear in the common speed to turning GH4169; Above all, in the four kinds of

tool material chosen for the experiment, KC5510 is better in turning GH4169 with common speed.

Acknowledgements

This work was supported by Natural Science Foundation of Heilongjiang Province (E201328).

References

[1] W. W. Liu, L. J. Zhu, C. F. Yao and X. C. Huang, Turning Technology of GH4169 Superalloy ,

J. Aeronautical Manufacturing Technology. 14 (2012) 48-51.

[2] R. D. Han and Q. X. Yu, Machining Difficult Materials. Machinery Industry Press. Chinese,

1996, pp. 66-69.

[3] F.Y. Yu, H. Wang, L. Wu and Y. Tu, Simulation and experiment of Titanium milling

mechanism of chip formation, J. Journal of Heilongjiang Institute of Science and Technoligy. 3

(2013) 227-230.

[4] X. Y. Wang, Q. X. Yu and S. Q. Pang, Reasonable Selection of Cutting Tool for High-

Temperature Alloy, J. Aeronautical Manufacturing Technology. 23 (2008) 52-55.

[5] Y. Qiao,Ai Z. J. Xing, and Z. Q. Liu, Study on Technology and Tool Materials for High Speed

Machining Superalloy, J. Tool Engineering. 06 (2010) 3-5.

464 High Speed Machining VI

High Speed Machining VI 10.4028/www.scientific.net/MSF.800-801 Experimental Research on the Selection of Tool Material in Turning Superalloy GH4169 10.4028/www.scientific.net/MSF.800-801.460