Provided is a surface-coated cutting tool combining superior heat resistance, superior wear resistance, and superior lubricity. A surface-coated cutting tool of the present invention includes a substrate and a coating formed on the substrate, and the coating is characterized in that the coating is formed by physical vapor deposition and includes one or more layers, that at least one of the one or more layers is a first coating layer, and that the first coating layer contains aluminum and nitrogen, has a thermal effusivity of 2,000 to 5,000 J·sec −1/2 ·m −2 ·K −1 , has a thickness of 0.2 to 5 μm, and has a crystal structure including a hexagonal structure.

Surface coated cutting tool

Ion-plated PVD TiN, TiCN, and high-ionization sputtered PVD TiAlN coatings were deposited on WC–6wt%Co hardmetal inserts. Microstructural and mechanical properties of the coatings and substrate were characterized. Coated tools were evaluated in turning of Inconel 718, medium carbon SAE 1045 steel, and ductile iron at low and high cutting speeds. TiAlN coated tools showed the best metalcutting performance, followed by the TiCN and TiN coated tools. The superior performance of the TiAlN coated tools, which was even greater at higher speeds, is related to the coating's higher resistance to abrasive and crater wear. These characteristics are a result of the higher hot hardness and oxidation resistance of TiAlN at the temperatures normally encountered at the tool tip during machining operations.

Performance of PVD TiN, TiCN, and TiAlN coated cemented carbide tools in turning

Coated tools constitute the majority of the tools applied in material removal processes, rendering the employment of uncoated ones as an exception. A broad growing market of coated cutting tools has been developed. Moreover, numerous material- and manufacturing-engineers have joint their expertise, aiming at developing coatings meeting the needs for processing the most difficult-to-cut materials at the most extreme cutting conditions. The emerging of new workpiece, tool and film materials, the evolution of sophisticated coatings’ characterization methods and the continuous need for higher productivity rates, maintain vivid the industrial and scientific interest for further advancing this field.

Cutting with coated tools: Coating technologies, characterization methods and performance optimization

Cutting tools with hard coatings have been successfully employed in the industry for almost 50 years. Nowadays, 85% of all cemented carbide tools are coated. There is an increasing demand for ever more efficient tools driven by the use of new workpiece materials as well as the demand for increased productivity of manufacturing processes. A historical review of the development of CVD and PVD processes shows a continuous improvement of successful coating materials through adjustments of the chemical composition and the coating architecture. Especially nanostructured PVD coatings managed to establish themselves on the market surprisingly quickly. Cutting tools are an excellent example for how the development of coated products is traced methodologically by means of a holistic view over the application. The demand for innovative tooling concepts will continue to exist in the future, as will the high potential for this aim to be achieved through high-performance coatings on improved cutting materials with adjusted tool design.

High-performance coatings for cutting tools

A coated cutting tool which has both chipping resistance and wear resistance, and a prolonged tool lifetime, and improves the roughness of a finished surface of a work. A coat cutting tool which has a hard coating layer (2) over the base material (1). The base material (1) consists of a bonding phase containing one or more kinds of iron family metals and a hard phase containing one or more kinds of substances selected from a group consisting of carbides nitrides, and oxides of group IVa, Va, VIa elements in the periodic table, and their solid solutions. Of the coating layer (2), substantially an edge ridge part (3), the area extending at least by 200 µm from a rake face side boundary part (6) of the edge ridge part toward the rake face side, and the area extending by at least 50 µm from a relief side boundary part (7) of the edge ridge part toward the relief are composed of a smooth face having a surface roughness (Rmax) of 0.2 µm or less (where the reference length is 5 µm)

Coated cutting tool

Adhesion measurements of chemically vapor deposited and physically vapor deposited hard coatings on WCCo substrates

High Temperature microhardness of hard coatings produced by physical and chemical vapor deposition

Provided is a coated cutting tool (10) having a binder enriched substrate (18). The coating includes at least one chemical vapor deposited (CVP) layer (30) and at least one physical vapor deposited (PVD) layer (34). The PVD layer contains residual compressive stresses.

Binder enriched cvd and pvd coated cutting tool

Crystalline γ-Al2O3 thin films have been deposited using reactive sputtering of aluminum targets. To prevent arcing, a dual magnetron configuration was used, while the targets were powered by a bipolar pulse power generator at 50 kHz. Scanning electron microscopy (SEM) revealed that films grown at 550 °C have a fine-grained morphology. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) analysis revealed that approximately 80% of the film has been condensed and grown in the γ-phase crystal structure. Film hardness and elastic modulus values obtained by nanoindentation on ∼2-μm-thick films were measured as approximately 25 GPa and 350 Gla respectively at 300 mN load. Constant particle bombardment of the growing films was important and the film morphology could be changed from a strong columnar to a dense compact structure.

Pulsed plasma-assisted PVD sputter-deposited alumina thin films

This review gives an account of the technological developments in hard coatings that have been commercially implemented in modern metal-cutting tools. Both CVD and PVD coatings have been successfully applied to cemented carbide metal-cutting inserts, in spite of the apparent competition between the two technologies. CVD coatings have evolved over the past 20 years with multilayer configurations that are still predominant today. PVD single-layer coatings have found niche applications, where conventional CVD coatings have not been particularly successful, and are expected to challenge standard CVD coatings with further advancements. Recently, a CVD/PVD layer combination has been commercially introduced. Scenarios for the development of newer coatings such as diamond and CBN are discussed. A failure mode diagram is proposed as a conceptual framework for metal-cutting tool design which takes into account the total system: the wear environment imposed by workpiece and machining parameters, corresponding tool failure modes and the synergy between hard coating and substrate.

Dennis T. Quinto

Papers

Adhesion measurements of chemically vapor deposited and physically vapor deposited hard coatings on WCCo substrates

High Temperature microhardness of hard coatings produced by physical and chemical vapor deposition

Binder enriched cvd and pvd coated cutting tool

Pulsed plasma-assisted PVD sputter-deposited alumina thin films

Technology perspective on CVD and PVD coated metal-cutting tools