Concept for Temperature Control in Broaching Nickel-Based Alloys

In production of safety critical components in aero engine manufacture, to date broaching is the most efficient process machining fir-tree slots in turbine discs. Machining highly thermal resistant Nickel-based alloys, manufacturers commonly use High Speed Steel (HSS) tools and work at low cutting speeds in order to stay at rather low tool wear rates and avoid part quality defects. The key variable affecting tool wear as well as part quality, as in most machining processes, is the temperature. Excessive temperatures in the cutting zone lead to enhanced tool wear on the one hand, and surface defects such as white layer formation and residual tensile stresses on the other hand. In this article, the temperature development is investigated for typical tool geometries and cutting parameters in broaching. Furthermore, the possibility of a temperature control using intermediate variables such as process forces is discussed, and potentials employing a control are explained.

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A Study on the Parameters in Hard Turning of High Speed Steel

International Journal of Materials Forming and Machining Processes ◽

10.4018/ijmfmp.2018070101 ◽

2018 ◽

Vol 5 (2) ◽

pp. 1-12

Author(s):

Krishnaraj Vijayan ◽

N. Gouthaman ◽

Tamilselvan Rathinam

Keyword(s):

Surface Roughness ◽

Tool Wear ◽

High Speed ◽

Hard Turning ◽

White Layer ◽

High Speed Steel ◽

Cutting Parameters ◽

Experimental Results ◽

Depth Of Cut ◽

Contributing Factors

The objectives of hard turning of high speed steel (HSS-M2 Grade) are to investigate the effect of cutting parameters on cutting force, tool wear and surface integrity. This article presents the experimental results of heat treated high speed steel machined in a CNC lathe using cubic boron nitride (CBN) tools. Turing experiments were carried out using central composite design (CCD) method. From the experiments the influence of cutting parameters and their interactions on cutting forces, temperature and surface roughness (Ra) were analyzed. Following this, multi response optimization was done to find the best combination of parameters for minimum force, minimum temperature and minimum surface roughness. The experimental results showed that the most contributing factors were feed followed by depth of cut and spindle speed. A white layer formed during hard turning was also analyzed by scanning electron microscope (SEM) and the results showed that it was greatly influenced by the speed and depth of cut. Tool wear was experiments were conducted at the optimum cutting conditions and it was noted that the tool satisfactorily performed up to 10 minutes at dry condition.

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Feasibility Study of the Effectiveness of Cryogenically Treated Ceramic Inserts for Pocket Milling Maneuvers

ASME 2009 International Manufacturing Science and Engineering Conference, Volume 2 ◽

10.1115/msec2009-84376 ◽

2009 ◽

Author(s):

Justin L. Milner ◽

Jeffrey A. Beers ◽

John T. Roth

Keyword(s):

Wear Resistance ◽

Tool Wear ◽

Feasibility Study ◽

High Speed ◽

Cryogenic Treatment ◽

Cutting Speed ◽

High Speed Steel ◽

Initial Study ◽

Machining Processes ◽

Cutting Speeds

Machining is a popular and versatile manufacturing process that is widely used in today’s industry when producing metallic parts; however, limited tool life can make this an expensive and time consuming fabrication technique. Consequently, methods that decrease the rate of tool wear and, thus, increase tool longevity are a vital component when improving the efficiency of machining processes. To this end, cryogenically treating cutting tools (especially high-speed steel tooling) is becoming more commonplace since research has shown that the treated tooling exhibits significantly higher wear resistance. At this point, however, the effect of cryogenic treatments on ceramic tooling has not been established. Considering this, the research herein presents a feasibility study on the effectiveness of using cryogenic treatments to enhance the wear resistance of WG-300 whisker-reinforced ceramic cutting inserts. To begin, the effect of the cryogenic treatment on the insert’s hardness is examined. Subsequently, tool wear tests are conducted at various cutting speeds. Through this study, it is shown that cryogenically treating the ceramic inserts decreases the rate of tool wear at each of the cutting speeds that were tested. However, the degree of wear resistance introduced by cryogenically treating the inserts proved to be highly dependent on the cutting speed, with slower speeds exhibiting greater improvements. Thus, based on this initial study, the cryogenic treatment of ceramic tooling appears to produce beneficial results, potentially increasing the overall efficiency of machining processes.

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Minimum Quantity Lubrication (MQL) and its Effect on Tool Wear During Miniature Drilling :an Experimental Study

International Journal of Engineering Materials and Manufacture ◽

10.26776/jemm.01.02.2016.04 ◽

2016 ◽

Vol 1 (2) ◽

pp. 65-70

Author(s):

Norsalawani Binti Mohamad ◽

Rubina Bahar

Keyword(s):

Tool Wear ◽

High Speed ◽

High Speed Steel ◽

Minimum Quantity Lubrication ◽

Limiting Factors ◽

Work Piece ◽

Machining Processes ◽

Minimum Quantity ◽

Tool Condition ◽

Overall Performance

Miniature drilling is widely used in industries including electronics and reconstructive surgeries to create small sized holes. Chip removal and effective supply of coolant are the two limiting factors that make the process more complex compared to other meso scale machining processes and also contribute to the tool wear. The tool wear in the process is mainly caused by the interaction, motion and chip production between the tool and work piece. Uniform supply of coolant must be ensured to reach the drilled cavity to keep the tool wear to a minimal level. This study includes experimental investigation of the tool condition after applying Minimum Quantity Lubrication (MQL) system as a greener approach as the name indicates. The tool condition with MQL has also been compared with dry and flood cooling. Two different types of drill bit materials (High Speed Steel and Carbide) have been tested under same experimental condition to drill through Aluminum Alloy 6061 and it has been found that overall performance in terms of tool condition after applying MQL was better compared to the other two methods. The overall wear propagation area was measured for both the conditions. It was seen, the wear propagation covered minimal area with MQL while for flood and dry condition wear was spread over a bigger area on flank.

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Effect of residual elements on the machinability of leaded free machining steels

Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences ◽

10.1098/rsta.1980.0077 ◽

1980 ◽

Vol 295 (1413) ◽

pp. 87-88 ◽

Cited By ~ 2

Keyword(s):

Wear Rate ◽

Tool Wear ◽

Tool Life ◽

High Speed ◽

Cutting Tool ◽

Cutting Tools ◽

Tool Material ◽

High Speed Steel ◽

Low Carbon ◽

Wear Rates

The machinability of a material can be defined in terms of the wear rate of the cutting tool used to machine the material. The lower the tool wear rate or the greater the tool life the better the machinability. The wear processes of cutting tools are complicated, but recent work has shown that cutting tool wear rates during machining can be directly related to tool material wear rates when rubbing in a modified crossed cylinder wear experiment (Mills & Akhtar 1975). The wear of cutting tools can be simulated by simple experiments. Here I present results on the effect of total residual levels in leaded low carbon free machining steels on the tool life of M2 high speed steel. The results will be discussed in terms of a simple wear model.

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Experimental Study on Tool Wear in NC Dry Milling Resin Sand Mold Materials

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.395-396.777 ◽

2013 ◽

Vol 395-396 ◽

pp. 777-781

Author(s):

Su Yu Wang ◽

Lin Lin Ma ◽

Wen Jie Yang

Keyword(s):

Tool Wear ◽

Wear Mechanism ◽

High Speed ◽

Tool Material ◽

High Speed Steel ◽

Cutting Parameters ◽

Sand Mold ◽

Mold Material ◽

Tool Wear Mechanism ◽

Coated Cemented Carbide

Experimental research was carried out to analyze the wear patterns of several tools which include high-speed steel (HSS), coated cemented carbide and ceramic tools, and to study the tool wear mechanism in milling resin sand mold materials. The main wear mechanism is abrasive wear and the dominant tool failure mode is flank wear. Different cutting parameters have different influence to the tool wear. In addition, it is essential to select suitable tool material with appropriate hardness. In this paper, the experiment results are contributive to choose proper cutting tool materials and parameters in milling resin sand mold material.

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Tribological Characterization of Machining at Very Small Contact Areas

Journal of Tribology ◽

10.1115/1.3195038 ◽

2009 ◽

Vol 131 (4) ◽

Cited By ~ 3

Author(s):

Michael R. Lovell ◽

P. Cohen ◽

Pradeep L. Menezes ◽

R. Shankar

Keyword(s):

High Speed ◽

Friction Mechanisms ◽

High Speed Steel ◽

Small Scale ◽

Machining Processes ◽

Macroscopic Theory ◽

Contact Areas ◽

Tribological Characterization ◽

Physical Phenomena

When machining miniaturized components, the contact conditions between the tool and the workpiece exhibit very small contact areas that are on the order of 10−5 mm2. Under these conditions, extremely high contact stresses are generated, and it is not clear whether macroscopic theories for the chip formation, cutting forces, and friction mechanisms are applicable. For this reason, the present investigation has focused on creating a basic understanding of the frictional behavior in very small scale machining processes so that evaluations of standard macroscale models could be performed. Specialized machining experiments were conducted on 70/30 brass materials using high-speed steel tools over a range of speeds, feeds, depths of cut, and tool rake angles. At each operating condition studied, the friction coefficient and the shear factor τk were obtained. Based on the experimental results, it was determined that the standard macroscopic theory for analyzing detailed friction mechanisms was insufficient in very small scale machining processes. An approach that utilized the shear factor, in contrast, was found to be better for decoupling the physical phenomena involved. Utilizing the shear factor as an analysis parameter, the parameters that significantly influence the friction in microscale machining processes were ascertained and discussed.

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Stability analysis for a single-point cutting tool deflection in turning operation

Advances in Mechanical Engineering ◽

10.1177/1687814019853188 ◽

2019 ◽

Vol 11 (6) ◽

pp. 168781401985318

Author(s):

Amon Gasagara ◽

Wuyin Jin ◽

Angelique Uwimbabazi

Keyword(s):

Cutting Forces ◽

High Speed ◽

Cutting Tool ◽

Single Point ◽

Three Dimensional ◽

High Speed Steel ◽

Cutting Parameters ◽

Depth Of Cut ◽

Beam Model ◽

Tool Deflection

In this article, a new model of regenerative vibrations due to the deflection of the cutting tool in turning is proposed. The previous study reported chatter as a result of cutting a wavy surface of the previous cut. The proposed model takes into account cutting forces as the main factor of tool deflection. A cantilever beam model is used to establish a numerical model of the tool deflection. Three-dimensional finite element method is used to estimate the tool permissible deflection under the action of the cutting load. To analyze the system dynamic behavior, 1-degree-of-freedom model is used. MATLAB is used to compute the system time series from the initial value using fourth-order Runge–Kutta numerical integration. A straight hard turning with minimal fluid application experiment is used to obtain cutting forces under stable and chatter conditions. A single-point cutting tool made from high-speed steel is used for cutting. Experiment results showed that for the cutting parameters above 0.1mm/rev feed and [Formula: see text]mm depth of cut, the system develops fluctuations and higher chatter vibration frequency. Dynamic model vibration results showed that the cutting tool deflection induces chatter vibrations which transit from periodic, quasi-periodic, and chaotic type.

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Conduction-Based Thermally Assisted Micromilling Process for Cutting Difficult-to-Machine Materials

Journal of Manufacturing and Materials Processing ◽

10.3390/jmmp4020034 ◽

2020 ◽

Vol 4 (2) ◽

pp. 34 ◽

Cited By ~ 1

Author(s):

Timo Platt ◽

Alexander Meijer ◽

Dirk Biermann

Keyword(s):

Tool Wear ◽

High Speed ◽

End Milling ◽

High Speed Steel ◽

High Strength ◽

Process Conditions ◽

Manufacturing Processes ◽

Central Process ◽

Workpiece Temperature ◽

Micro End Milling

The increasing demand for complex and wear-resistant forming tools made of difficult-to-machine materials requires efficient manufacturing processes. In terms of high-strength materials; highly suitable processes such as micromilling are limited in their potential due to the increased tool loads and the resulting tool wear. This promotes hybrid manufacturing processes that offer approaches to increase the performance. In this paper; conduction-based thermally assisted micromilling using a prototype device to homogeneously heat the entire workpiece is investigated. By varying the workpiece temperature by 20 °C < TW < 500 °C; a highly durable high-speed steel (HSS) AISI M3:2 (63 HRC) and a hot-work steel (HWS) AISI H11 (53 HRC) were machined using PVD-TiAlN coated micro-end milling tools (d = 1 mm). The influence of the workpiece temperature on central process conditions; such as tool wear and achievable surface quality; are determined. As expected; the temporary thermal softening of the materials leads to a reduction in the cutting forces and; thus; in the resulting tool wear for specific configurations of the thermal assistance. While only minor effects are detected regarding the surface topography; a significant reduction in the burr height is achieved.

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Prediction of Tool Lifetime and Surface Roughness for Nickel-Based Waspaloy

Advances in Materials Science and Engineering ◽

10.1155/2020/2013487 ◽

2020 ◽

Vol 2020 ◽

pp. 1-12

Author(s):

Shao-Hsien Chen ◽

Chung-An Yu

Keyword(s):

Surface Roughness ◽

Tool Wear ◽

High Speed ◽

Cutting Speed ◽

High Strength ◽

Cutting Parameters ◽

Experimental Results ◽

Predictive Values ◽

Actual Surface ◽

Wide Range

In recent years, most of nickel-based materials have been used in aircraft engines. Nickel-based materials applied in the aerospace industry are used in a wide range of applications because of their strength and rigidity at high temperature. However, the high temperatures and high strength caused by the nickel-based materials during cutting also reduce the tool lifetime. This research aims to investigate the tool wear and the surface roughness of Waspaloy during cutting with various cutting speeds, feed per tooth, cutting depth, and other cutting parameters. Then, it derives the formula for the tool lifetime based on the experimental results and explores the impacts of these cutting parameters on the cutting of Waspaloy. Since the impacts of cutting speed on the cutting of Waspaloy are most significant in accordance with the experimental results, the high-speed cutting is not recommended. In addition, the actual surface roughness of Waspaloy is worse than the theoretical surface roughness in case of more tool wear. Finally, a set of mathematical models can be established based on these results, in order to predict the surface roughness of Waspaloy cut with a worn tool. The errors between the predictive values and the actual values are 5.122%∼8.646%. If the surface roughness is within the tolerance, the model can be used to predict the residual tool lifetime before the tool is damaged completely. The errors between the predictive values and the actual values are 8.014%∼20.479%.

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