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Cutting tools obtained from nearly full dense Ti(C, N)-based materials, with limited percentage of metal binder, were tested in turning and milling operations. Microstructure and mechanical properties were investigated and related to starting composition and processing conditions. Wear mechanisms were studied and compared to those of some commercial tools, in order to better understand key aspects due to thermal wear mechanisms (mainly diffusion and oxidation) and mechanical wear mechanisms, which both contributed to the material degradation. In particular amount and stoichiometry of the Ti(C, N) hard phase influence the oxidation behaviour and the thermal conductivity, while the low content of metal binder allows the achievement of high relative final density. Compared to commercial competitors, under the adopted cutting conditions the newly Ti(C, N)-based tools showed improved performance in machining carbon steel, and quench and tempered steel.

An experimental analysis of the cutting performance of poly-crystalline diamond (PCD) and chemical vapour deposition (CVD) diamond coated inserts is presented. Results are discussed in terms of wear phenomena with application to turning of two metal matrix composites (MMCs).

A set of ceramic and cermet targets were used in erosion tests by solid particle impingement under oblique and orthogonal impacts. The experimental results are presented in terms of steady-state erosion rate and crater morphology. A comparison of anti-erosion performance is proposed and discussed on the basis of hardness and structure of the target materials.

Fundamentals of fuzzy sets and fuzzy logic are introduced from a theoretic point of view. Practical approaches are developed and focused on real time problems related to machining systems. Techniques for design and implementation of fuzzy systems are presented in the framework of control systems engineering. Applications of fuzzy logic-based systems to monitoring and control of metal working processes, and to problems of related interest are reviewed.

Some innovative, commercially available and experimental PVD coatings deposited on hard metal and cermet end mills are investigated using laboratory tests. The uncoated and coated tools are used in the high-speed dry cutting of a steel and the wet cutting of an aluminium-based alloy. Finishing operations are performed under a set of milling conditions. Tool life is used as a criterion for a comparative evaluation of the coating performance, based also on the real-time monitoring of cutting forces and power consumption. The results are discussed in terms of machining costs per unit of metal volume removed.

The anti-wear behaviour of some fine ceramics (including oxides, nitride-based, mixed, and composites) for tool materials is investigated in a set of laboratory experiments. The experimental trials are designed in order to monitor wear patterns obtained in extreme conditions (even unusual for the customary industrial use of such materials) from a two-fold point of view, as described hereafter. These materials are used for targets in erosion tests under oblique and orthogonal impacting conditions. Also, the same materials are used for cutting tools in continuous dry turning experiments, using a hypereutectic aluminium-based alloy (containing also: Si 17–19%, Fe 1.20% max, Mg 0.4–0.7%) for the work-material. The results of erosion tests are discussed in terms of crater wear, together with the results of the machining experiments in terms of flank wear.

A computer-based adaptive system for the closed-loop control of the cutting temperature is modelled and designed for application to a lathe turning process. The cutting temperature is estimated through e.m.f. measurements obtained by using a standard thermocouple embedded in the tool holder. The control objective is to maximise the metal removal rate subject to constraints on tool decay related to temperature-dependent wear mechanisms. A real-time monitoring and control strategy is implemented aiming at compensating for process dynamics variations according to a self-tuning regulator scheme.

A commercial cermet grade SPKN 1203 ED-TR is PVD coated by using ion-plating and cathodic arc techniques to deposit thin mono- and multi-layers composed of: TiN, Ti2N, TiCN, TiAlN, TiCN+TiCN, TiCN+Ti2N and TiN+TiCN. Dry face milling experiments were performed on AISI-SAE 1045 steel. A comparative performance evaluation of uncoated and coated inserts is provided on the base of flank wear measurements.

An experimental cermet insert developed using a rich binder component with a view to obtaining a high toughness is coated by TiN and Ti(C, N) thin films by a PVD technique. The uncoated and coated inserts were used in continuous and interrupted turning test. Results are compared in terms of tool life and discussed from the point of view of the influence of the experimental coatings on the cutting performance.

The wear behaviour of cermet materials commercially available for cutting tool applications is investigated. Four insert types of diverse cermet compositions are used in dry face milling of steel AISI-SAE 1045 and in erosion tests under oblique and orthogonal impacting conditions. Results of the milling tests are discussed in terms of tool-life, flank and crater wear, and resistance to mechanical impacts. Results of erosion tests are discussed in terms of steady-state erosion rate and crater morphology. A possible correlation of the wear modes observed both in milling and erosive tests is proposed and discussed, based on a comparative experimental study, focusing on the insert material and mechanical characteristics.

Adaptive monitoring and control systems are focused from the twofold point of view of control techniques and applications to machining processes. Methods for designing computer-based systems, digital models for implementing real-time algorithms, and sensors for on-line monitoring are dealt with. A gap to be filled between theoretical potential of adaptive systems and their industrial use is pointed out and discussed, based on an annotated survey of the relevant literature.

Specimens of alumina, zirconia-toughened aluminas, whisker-reinforced alumina, mixed alumina/titanium carbide, silicon nitride and silicon nitride/titanium nitride are used as target materials in erosion tests. A comparative analysis of the damage is developed in terms of material loss and crater morphology. The influence of hardness and fracture toughness on the material property to resists to impact erosion and abrasive wear is also discussed. As a result, a qualitative rating of the performance is proposed.

The paper presents the results of investigations of the 5% cobalt and 2% molybdenum additions in the W-Mo-V and W-V high-speed steels of the 9-2-2, 11-2-2 and 11-0-2 types with economically designed chemical composition on the wear mechanism during cutting and erosion tests. The 5% cobalt addition results in increasing the secondary hardness effect by 1.6 to 1.9 HRC, depending on a steel grade. Secondary hardness effect is caused by the dispersive carbides of the M4C3 type and martensite transformation of the retained austenite. The maximum secondary hardness effect about 66.3-67.6 HRC, depending on a grade of steel, occurs in each steel after tempering at 540oC and austenitizing at 1240oC. The 5% cobalt addition results in enhancing the working properties of tools, longer tool life and makes it possible to increase cutting speed by about 50%, compared with the steels of identical concentration of other alloying elements but without cobalt addition. Cobalt does not have any significant influence on erosion resistance, which is independent of the steel hardness but depends on molybdenum addition in steel.

This paper presents results of investigations regarding the erosion resistance of TiN and Ti(C,N) PVD coatings deposited onto W-Mo-V high-speed steel of 9-2-2 + Si and 11-2-2 + Si type with Nb or Ti additions. Quantitative metallography methods as well as mass loss and the 3D measurements of craters created are employed to evaluate the erosion resistance of the investigated coatings. Ti(C,N) coatings attain double erosion resistance compared to TiN coatings. The influence of surface topography on the erosion resistance of PVD vacuum-arc method coatings is described. It was found that the investigated coatings are not affected by the type of high-speed steel constituting the substrate.