Metal on metal - removal of an extruding mandibular titanium reconstruction plate with a high-speed electrical surgical drill

Results of a four-year Advanced Machining Research Program (AMRP) to provide a science base for faster metal removal through high-speed machining (HSM), high-throughput machining (HTM) and laser-assisted machining (LAM) are presented. Emphasis was placed on turning and milling of aluminum-, nickel-base-, titanium-, and ferrous alloys. Experimental cutting speeds ranged from 0.0013 smm (0.004 sfpm) to 24,500 smm (80,000 sfpm). Chip formation in HSM is found to be associated with the formation of either a continuous, ribbon-like chip or a segmental (or shear-localized) chip. The former is favored by good thermal properties, low hardness, and fcc/bcc crystal structures, e.g., aluminum alloys and soft carbon steels, while the latter is favored by poor thermal properties, hcp structure, and high hardness, e.g., titanium alloys, nickel base superalloys, and hardened alloy steels. Mathematical models were developed to describe the primary features of chip formation in HSM. At ultra-high speed machining (UHSM) speeds, chip type does not change with speed nor does tool wear. However, at even moderately high speeds, tool wear is still the limiting factor when machining titanium alloys, superalloys, and special steels. Tool life and productivity can be increased significantly for special applications using two novel cutting tool concepts – ledge and rotary. With ledge inserts, titanium alloys can be machined (turning and face milling) five times faster than conventional, with long tool life (~ 30 min) and cost savings up to 78 percent. A stiffened rotary tool has yielded a tool life improvement of twenty times in turning Inconel 718 and about six times when machining titanium 6A1-4V. Significantly increased metal removal rates (up to 50 in.3/min on Inconel 718 and Ti 6A1-4V) have been achieved on a rigid, high-power precision lathe. Continuous wave CO2 LAM, though conceptually feasible, limits the opportunities to manufacture DOD components due to poor adsorption (~ 10 percent) together with high capital equipment and operating costs. Pulse LAM shows greater promise, especially if new laser source concepts such as face pump lasers are considered. Economic modeling has enabled assessment of HSM and LAM developments. Aluminum HSM has been demonstrated in a production environment and substantial payoffs are indicated in airframe applications.

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The Ledge Tool: A New Cutting Tool Insert

Journal of Engineering for Industry ◽

10.1115/1.3185990 ◽

1985 ◽

Vol 107 (2) ◽

pp. 99-106 ◽

Cited By ~ 6

Author(s):

R. Komanduri ◽

M. Lee

Keyword(s):

Titanium Alloys ◽

High Speed ◽

Cutting Tool ◽

Metal Removal ◽

Face Milling ◽

Cemented Carbide ◽

Depth Of Cut ◽

Peripheral Milling ◽

Cemented Carbide Tool ◽

Edge Wear

The salient features of a simple, wear-tolerant cemented carbide tool are described. Results are presented for high-speed machining (3 to 5 times the conventional speeds) of titanium alloys in turning and face milling. This tool, termed the ledge cutting tool, has a thin (0.015 to 0.050 in.) ledge which overhangs a small distance (0.015 to 0.060 in.) equal to the depth of cut desired. Such a design permits only a limited amount of flank wear (determined by the thickness of the ledge) but continues to perform for a long period of time as a result of wear-back of the ledge. Under optimum conditions, the wear-back occurs predominantly by microchipping. Because of geometric restrictions, the ledge tool is applicable only to straight cuts in turning, facing, and boring, and to face milling and some peripheral milling. Also, the maximum depth of cut is somewhat limited by the ledge configuration. In turning, cutting time on titanium alloys can be as long as ≈ 30 min. or more, and metal removal of ≈ 60 in.3 can be achieved on a single edge. Wear-back rates in face milling are about 2 to 3 times higher than in straight turning. The higher rates are attributed here to the interrupted nature of cutting in milling. Use of a grade of cemented carbide (e.g., C1 Grade) which is too tough or has too thick a ledge for a given application leads to excessive forces which can cause gross chipping of the ledge (rapid wear) and/or excessive deflection of the cutting tool with reduced depth of cut. Selection of a proper grade of carbide (e.g., Grades C2, C3, C4) for a given application results in uniform, low wear-back caused by microchipping. Because of the end cutting edge angle (though small, ≈ 1 deg) used, the ledge tool can generate a slight taper on very long parts; hence an N.C. tool offset may be necessary to compensate for wear-back. The ledge tool is found to give excellent finish (1 to 3 μm) in both turning and face milling. In general, conventional tooling with slight modifications can be used for ledge machining. The ledge tool can also be used for machining cast iron at very high speeds.

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Laser Balancing Demonstration on a High-Speed Flexible Rotor

Volume 1A: Gas Turbines ◽

10.1115/79-gt-56 ◽

1979 ◽

Author(s):

R. S. DeMuth ◽

D. P. Fleming ◽

R. A. Rio

Keyword(s):

Material Removal ◽

High Speed ◽

Metal Removal ◽

Flexible Rotor ◽

Test Rig ◽

Laser Material ◽

Removal Method ◽

Before And After ◽

Optical Configuration ◽

Neodymium Glass

This paper describes a flexible rotor system used for two-plane laser balancing and an experimental demonstration of the laser material removal method for balancing. A laboratory test rotor was modified to accept balancing corrections using a laser metal removal method while the rotor is at operating speed. The laser setup hardware required to balance the rotor using two correction planes is described. The test rig optical configuration and a neodymium glass laser were assembled and calibrated for material removal rates. Rotor amplitudes before and after balancing, trial and correction weights, rotor speed during operation of laser, and balancing time were documented. The rotor was balanced through the first bending critical speed using the laser material removal procedure to apply trial weights and correction weights without stopping the rotor.

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Study of the Efficiency of Ultrasonic Turning of Heat-Resistant Alloys with Tools from Mineral Ceramics

MATEC Web of Conferences ◽

10.1051/matecconf/201929701011 ◽

2019 ◽

Vol 297 ◽

pp. 01011

Author(s):

Nguyen Khanh Toan ◽

Nikolay Mezin

Keyword(s):

Nickel Alloys ◽

High Speed ◽

Metal Removal ◽

Ultrasonic Field ◽

Significant Loss ◽

Field Energy ◽

Thermal Processes ◽

Heat Resistant ◽

Defective Layer ◽

Loss Of Strength

The results of the study of the effectiveness of high-speed ultrasonic turning of billets from heat-resistant nickel alloys without coolant are given. It was established that the introduction of ultrasonic field energy into the shaping zone reduces the contact temperature by 10–15% and the cutting force by 20–30%. However, this does not cause a decrease in metal removal performance due to a significant loss of strength and ease of cutting at temperatures above 800 C. As follows from the results, ultrasound helps to reduce the thickness of the defective layer, the formation of which is caused by thermal processes and phase transformations with the appearance of tensile residual stresses in the surface layer.

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Tool-Life Optimization in High-Speed Milling of Aeronautical Aluminum Alloy 7050-T7451

Materials Science Forum ◽

10.4028/www.scientific.net/msf.626-627.117 ◽

2009 ◽

Vol 626-627 ◽

pp. 117-122

Author(s):

Y.Z. Pan ◽

Xing Ai ◽

Jun Zhao ◽

X.L. Fu

Keyword(s):

Aluminum Alloy ◽

Tool Life ◽

High Speed ◽

Metal Removal ◽

Removal Rate ◽

Cutting Speed ◽

Least Square ◽

High Speed Milling ◽

Solid Carbide ◽

Multi Linear Regression

A new approach is presented to optimize the tool life of solid carbide end mill in high-speed milling of 7050-T7451 aeronautical aluminum alloy. In view of this, the multi-linear regression model for tool life has been developed in terms of cutting speed and feed per tooth by means of central composite design of experiment and least-square techniques. Variance analyses were applied to check the adequacy of the predictive model and the significances of the independent parameters. Response contours of tool life and metal removal rates were generated by using response surface methodology (RSM). The analysis results show that it is possible to select an optimum combination of cutting speed and feed per tooth that improves metal removal rate without any sacrifice in tool life.

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High-speed frictional slip at metal-on-metal interfaces

International Journal of Plasticity ◽

10.1016/j.ijplas.2008.12.006 ◽

2009 ◽

Vol 25 (4) ◽

pp. 612-634 ◽

Cited By ~ 25

Author(s):

Fuping Yuan ◽

Nai-Shang Liou ◽

Vikas Prakash

Keyword(s):

High Speed ◽

Metal On Metal ◽

Metal Interfaces ◽

Frictional Slip

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An Analytical One-Dimensional Penetration Model

Volume 4: Fluid-Structure Interaction ◽

10.1115/pvp2008-61155 ◽

2008 ◽

Author(s):

Sarah Reichwein ◽

Stanley E. Jones

Keyword(s):

Penetration Depth ◽

High Speed ◽

Large Data ◽

Parameter Analysis ◽

Strength Parameters ◽

Data Set ◽

Penetration Process ◽

Dramatic Effect ◽

One Dimensional ◽

Metal On Metal

In an earlier paper, the authors extended the small parameter analysis of the classic Tate Equations presented by Walters, et al and to the modified penetration equations introduced previously by Jones, et al. The purpose of this extension was to provide an explicit solution to a complex system of nonlinear penetration equations in which penetrator mushrooming was considered, as well as erosion. This has a dramatic effect on the prediction of penetration depth for reasonable values of the strength parameters in the problem. The results were very encouraging and led to our increased understanding of the penetration process. In this paper, we further modify the equations for penetration depth by replacing the fundamental kinematical length relation, considered earlier, by one which was introduced by Wilson, et al. This change does not complicate the system because the mushroom strain is constant, but it does produce some significant changes. In this paper, the results of Cinnamon, et al are used to estimate the mushroom strain. However, instead of applying this result directly, we employ an averaging process to accommodate deviations from cylindrical crater geometry. The changes result in improved penetration depth estimates in high speed metal on metal impacts. A large data set is analyzed using the new results. Application to heavy metal impacts against armor targets is considered as an example.

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Tribology of high-speed metal-on-metal sliding at near-melt and fully-melt interfacial temperatures

Wear ◽

10.1016/s0043-1648(01)00698-6 ◽

2001 ◽

Vol 249 (8) ◽

pp. 672-686 ◽

Cited By ~ 22

Author(s):

Makoto Okada ◽

Nai-Shang Liou ◽

Vikas Prakash ◽

Kazuhisa Miyoshi

Keyword(s):

High Speed ◽

Metal On Metal

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The Effect of Tool Length on Stable Metal Removal Rate in High Speed Milling

CIRP Annals ◽

10.1016/s0007-8506(07)62839-x ◽

1998 ◽

Vol 47 (1) ◽

pp. 307-310 ◽

Cited By ~ 38

Author(s):

S. Smith ◽

W.R. Winfough ◽

J. Halley

Keyword(s):

High Speed ◽

Metal Removal ◽

Removal Rate ◽

Metal Removal Rate ◽

High Speed Milling

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Current Trends in High-Speed Machining

Journal of Manufacturing Science and Engineering ◽

10.1115/1.2836806 ◽

1997 ◽

Vol 119 (4B) ◽

pp. 664-666 ◽

Cited By ~ 79

Author(s):

S. Smith ◽

J. Tlusty

Keyword(s):

Structural Design ◽

High Speed ◽

Metal Removal ◽

Design Tool ◽

Cutting Performance ◽

High Speed Machining ◽

Research Areas ◽

Current Trends ◽

Solid Carbide ◽

Cutting Speeds

The focus of the majority of high-speed machining research has been directed toward improving metal removal rates. Tool materials capable of withstanding high cutting speeds have become available (silicon nitride for cast iron, solid carbide for aluminum, and superabrasives for hardened steels), and the focus of research has shifted to maximizing the cutting performance of the machine tool. Measurement of cutting performance, chatter avoidance, structural design, tool retention, and axis control have become important research topics. The purpose of this paper is to provide an overview of the state of the art in high-speed machining and to provide our view of the emerging research areas.

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