Pretreatment of substrate surface for improved adhesion of diamond films on hard metal cutting tools

Diamond film coated hard metal cutting tools are indispensible for high efficiency machining of materials which are difficult to cut by ordinary tools, and are successfully used in the dry cutting of high silicon content Al-Si cast alloys, graphite, carbon reinforced composite (CRFC) and metal matrix composite (MMC) , ceramics, and many other materials. In the present presentation, a novel process of High Current Extended DC Arc (HCEDCA) plasma CVD for mass production of diamond film coated hard metal cutting tools is presented. Besides, a novel process for the pretreatment of the hard metal cutting tool substrate, which involves the idea of “surface engineering” consisting of boronizing and alkaline and acidic etching is also discussed, by which the adhesion of the diamond film coating to the hard metal substrate can be greatly enhanced. Highly adherent and uniform diamond film coatings are successfully obtained. Diamond film coated WC-6wt%Co indexable tool bits, drills, endmill samples have been produced and been shown having excellent cutting performance by field cutting tests in dry cutting of Al-12%Si cast alloy and Al-15% SiC MMC materials.

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Paris Salon showcases hard metal cutting tools

Metal Powder Report ◽

10.1016/s0026-0657(13)70123-1 ◽

2013 ◽

Vol 68 (4) ◽

pp. 22-23

Author(s):

Ken Brookes

Keyword(s):

Metal Cutting ◽

Cutting Tools ◽

Hard Metal ◽

Paris Salon

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A new quick-stop device to study the chip formation mechanism in metal cutting: Computational and experimental investigation

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/09544062211034210 ◽

2021 ◽

pp. 095440622110342

Author(s):

Mohamed Baccar Mhamdi ◽

Wajdi Rajhi ◽

Mohamed Boujelbene ◽

Sahbi Ben Salem ◽

Sonia Ezeddini ◽

...

Keyword(s):

Chip Formation ◽

Metal Cutting ◽

Cutting Tools ◽

Cutting Parameters ◽

Hard Metal ◽

Formation Mechanisms ◽

Machining Parameters ◽

Chip Formation Mechanism ◽

Aisi D2 ◽

Stop Test

Understanding the chip formation mechanisms during machining is an important factor to facilitate the choice of cutting tools and machining parameters. Despite the appearance of new sophisticated methods and advanced equipment, the technique so called quick-Stop Test (QST) remains efficient, less costly, and easier to apply in the investigation of chip formation in cutting process. In present paper a new Quick-Stop Device QSD is designed, numerically simulated, implemented, and tested. The reformed QST technique uses a QSD device which operates on the modified Charpy pendulum. Accordingly, design of new QSD is presented and deeply described, and 2D FE modeling of the new QST, including the application of the appropriate boundary conditions, has been carried out. Moreover, chip formation and morphology for different cutting conditions have been effectively simulated. Subsequently, quick stop cutting operations including metal cutting tests of high alloyed tool steel (AISI D2) using fabricated new QSD are performed. Preliminary results of quick-stop experiment from current investigation prove the effectiveness of the new designed QSD in matter of rigidity, safety, and absence of vibration, while providing a fast set up time and allowing extremely short workpiece-cutting tool separation time and guarantee the generation of chip with its root. The photomicrographs of chip root samples gathered from hard metal cutting experiments including various cutting speeds machining conditions, enables clear observation of segmented chip formation mechanisms, thereby, highly promising the new designed QSD for the purpose of investigation of the different cutting parameters influencing the chip formation and morphology.

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Study and Development of a Multilayered Coating to Improve Hard Metal Cutting Tools Performances

Materials Science Forum ◽

10.4028/www.scientific.net/msf.941.1656 ◽

2018 ◽

Vol 941 ◽

pp. 1656-1661

Author(s):

Federico Simone Gobber ◽

Mario Rosso

Keyword(s):

Metal Cutting ◽

Multilayer Coating ◽

Cutting Tools ◽

Hard Metal ◽

Point Of View ◽

Thin Layers ◽

Mechanical Working ◽

Heat Resistant Alloy ◽

Experimental Cutting ◽

The Difference

The use of coated hard metal is spread in all fields of mechanical working, both forming and machining. Different hard metals are used based on their mechanical characteristic that strongly depends on composition and grain size. Substrates such as HSS and WC – Co are typically coated with PVD thin layers in applications such as metalworking and cutting; thus lot of efforts are put in researching this specific field. Coating composition, and coating architecture are paramount topics in the subsject of surface anti – wear thin films. The focus of this study is to analyze the difference between two AlTiN coatings, a monolayer and a multilayer with gradient composition, from the point of view of microstructure and adhesion. Experimental cutting tests were done to characterize the behavior of the coating in face milling of AISI 660 heat resistant alloy: varying cutting speeds from 15 to 40 m/min it was finally assessed that a multilayer coating can give higher tool life with respect to a monolayer coating of the same composition.

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Characteristics of Electroplated Nickel Layer on Tungsten Carbide

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.315.73 ◽

2013 ◽

Vol 315 ◽

pp. 73-77 ◽

Cited By ~ 3

Author(s):

Hassan A. Wahab ◽

M.Y. Noordin ◽

Mohammad Sakhawat Hussain ◽

S. Izman

Keyword(s):

Tungsten Carbide ◽

Nickel Coating ◽

Substrate Surface ◽

Cutting Tools ◽

Hard Metal ◽

Separation Distance ◽

Nickel Layer ◽

Nickel Deposition ◽

Hardness Tester ◽

Materials Used

Diamond coating on tungsten carbide (WC-Co) cutting tools with cobalt binder experiences delaminating failure due to the deleterious effect of cobalt. One of the methods used to reduce this effect is by coating an interlayer onto the substrate surface prior to diamond deposition. Different materials have been used as an interlayer which is normally deposited to the substrate surface using CVD and PVD techniques. Among different materials used as interlayer on WC-Co, nickel is considered as an attractive candidate due its good chemical and physical properties. In this study the potential of the electroplating technique for deposition of nickel interlayer on WC-Co will be investigated. Nickel deposition on WC-6%Co substrate was carried out by electroplating in a standard watts solution at constant plating parameters (Current: 0.1 Amp, electric potential: 1.0 V and pH: 3.5). The gap between anode and cathode was varied (5mm, 10mm and 15mm). The nickel coating formed on the hard metal surface was characterized in terms of the coating thickness, layer uniformity and coating hardness by using SEM and the micro hardness tester. Based on the results, desirable nickel coating properties were obtained when the separation distance between anode and cathode was 15mm.

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Effect of Solid-State Laser Parameters on the Surface’s Topography Formation During Texturization of Hard Metal Cutting Tools

Journal of Aerospace Technology and Management ◽

10.5028/jatm.v7i1.411 ◽

2015 ◽

Vol 7 (1) ◽

pp. 63-69 ◽

Cited By ~ 3

Author(s):

Patrícia Helena De Oliveira Teixeira ◽

Adriano Gonçalves dos Reis ◽

Andreas Janssen

Keyword(s):

Solid State ◽

Metal Cutting ◽

Cutting Tools ◽

Hard Metal ◽

Solid State Laser ◽

State Laser ◽

Laser Parameters

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Characterization of homoepitaxial diamond films by Electron microscopy

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100088713 ◽

1991 ◽

Vol 49 ◽

pp. 880-881

Author(s):

D.P. Malta ◽

S.A. Willard ◽

R.A. Rudder ◽

G.C. Hudson ◽

J.B. Posthill ◽

...

Keyword(s):

Electron Microscopy ◽

Surface Defects ◽

Substrate Surface ◽

Diamond Films ◽

Chemical Vapor ◽

Polycrystalline Diamond ◽

Large Degree ◽

Rf Plasma ◽

Semiconducting Diamond

Semiconducting diamond films have the potential for use as a material in which to build active electronic devices capable of operating at high temperatures or in high radiation environments. A major goal of current device-related diamond research is to achieve a high quality epitaxial film on an inexpensive, readily available, non-native substrate. One step in the process of achieving this goal is understanding the nucleation and growth processes of diamond films on diamond substrates. Electron microscopy has already proven invaluable for assessing polycrystalline diamond films grown on nonnative surfaces.The quality of the grown diamond film depends on several factors, one of which is the quality of the diamond substrate. Substrates commercially available today have often been found to have scratched surfaces resulting from the polishing process (Fig. 1a). Electron beam-induced current (EBIC) imaging shows that electrically active sub-surface defects can be present to a large degree (Fig. 1c). Growth of homoepitaxial diamond films by rf plasma-enhanced chemical vapor deposition (PECVD) has been found to planarize the scratched substrate surface (Fig. 1b).

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