TATMO V

In the field of mechanical engineering, engineers are always looking for ways to improve the properties of materials. Cryogenic treatment of tooling steels is a proven technology to increase wear resistance and extend intervals between component replacements. The main idea of this paper is to apply Taguchi method to optimize cutting parameters in turning operation using cryogenic treated (CT) and untreated (UT) high speed steel (HSS) tools, so that the scope of cryogenic treatment on HSS tool material may be presented for the benefit of medium and small scale industry using HSS tools for cutting operation. Taguchi L25 orthogonal array is employed to study the performance characteristics in turning operations of AISI 1020 steel bars using CT and UT HSS tools. The microstructure has been found more refined and uniformly distributed after cryogenic treatment of HSS tool. It has been observed that optimum machining parameters in both the cases (CT HSS and UT HSS tools) are higher cutting speed (49.9 to 75.7 m/min.), lower feed rate (0.15 mm/rev.), medium depth of cut (0.40 mm). Analysis of variance (ANOVA) indicates that the cutting speed is most significant parameter followed by feed rate in case of CT HSS tool and depth of cut in case of UT HSS tool.

In this study, a cutting tool is developed from duplex stainless steel (DSS) using the superplastic boronizing technique. The feasibility of the development process is studied, and the cutting performances of the cutting tool are evaluated and compared with commercially available carbide and high-speed steel (HSS) tools. The superplastically boronized (SPB) cutting tool yielded a dense boronized layer of 50.5 µm with a surface hardness of 3956 HV. A coefficient of friction value of 0.62 is obtained, which is lower than 1.02 and 0.8 of the carbide and HSS tools. When tested on an aluminum 6061 surface under dry condition, the SPB cutting tool is also able to produce turning finishing below 0.4 µm, beyond the travel distance of 3000 m, which is comparable to the carbide tool, but produces much better results than HSS tool. Through superplastic boronizing of DSS, it is possible to produce a high-quality metal-based cutting tool that is comparable to the conventional carbide tool.

This article discusses the classifications of high-speed tool steels and describes alloying elements and their effects on the properties of high-speed tool steels. It analyzes the heat treatment of high-speed tool steels, namely, preheating, austenitizing, quenching, and tempering. Surface treatments for the high-speed tool steels are reviewed. The article emphasizes the properties and applications of high-speed tool steels and provides information on the factors in selecting high-speed tool steels.

Micro-Melt 23 is a general-purpose alloy with a good combination of properties. This high-speed tool steel is made from powder with all its inherent values. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on corrosion and wear resistance as well as forming, heat treating, machining, and powder metal forms. Filing Code: TS-627. Producer or source: Carpenter Powder Technologies.

BETHLEHEM M-2 is a molybdenum-tungsten type of high-speed steel. In general, it can be used for the same applications as the 18 tungsten-4 chromium-1 vanadium (AISI Type T1) high-speed steel. Its higher carbon content (relative to Type T1) and balanced composition produce properties applicable to all general-purpose high-speed uses. This datasheet provides information on composition, physical properties, hardness, and elasticity as well as fracture toughness. It also includes information on forming, heat treating, machining, and surface treatment. Filing Code: TS-319. Producer or source: Bethlehem Steel Corporation.

- This paper presents a comprehensive literature review and finite element analysis (FEA) of chip formation in metal cutting using Abaqus, comparing soft high-speed steel (HSS) tools and hard tungsten-carbide (WC) tools across various workpiece materials. Soft HSS tools are analyzed for difficult-to-machine alloys, including cast iron, titanium alloys, high-carbon steel, and hardened steel, while hard WC tools are analyzed for soft non-ferrous metals, such as aluminium, copper, zinc, and lead. Key machining parameters—cutting speed, feed, cutting temperature, chip morphology, and lubrication type—are summarized. The study highlights the effects of tool hardness and workpiece material on chip formation, cutting-zone temperature, and tool life, providing guidance for literature-based FEA modeling and future experimental validation. Key Words - Chip formation, Finite Element Analysis (FEA), Abaqus, HSS Tool, Tungsten-Carbide (WC) Tool, Aluminium, Copper, Zinc, Lead, Cast Iron, Titanium Alloy, Steel, Machining Parameters.

There has been a growing concern about the reactivity at the tool/work-piece interface during machining, leading to lower tool life. The problem is more severe especially in the case of aerospace alloys such as Ti-6Al-4V and stainless steels. Recently, a new ultra hard ceramic material, AlMgB14, was reported with properties that show considerable promise as a cutting tool material for machining titanium alloys [1]. This paper investigates the chemical wear behavior of AlMgB14, in the machining of aerospace alloys. The mechanical properties of AlMgB14 are compared with leading cutting tool materials (WC-Co, Al2O3SiCw-TiC and Al2O3-TiC), which are used extensively in machining titanium and ferrous alloys. Materials characterization of candidate tool materials shows that AlMgB14 exhibits superior hardness, fracture toughness and abrasive wear resistance as compared to the other cutting tool materials. We also report on a study of chemical reactivity of tool materials (AlMgB14 and WC-6%Co) in machining various alloys such as Ti-6Al-4V and Fe-18Ni-8Cr. The chemical reactivity was investigated using diffusion tests conducted in vacuum at 1000°C for 120 hrs. Transverse sections of couples were characterized using electron probe micro analysis (EPMA), to determine the extent of diffusion zones. The results show that AlMgB14 shows considerably less reactivity with titanium alloys when compared with cemented carbide cutting tools. It was also observed that the boride reacts significantly with the iron based Fe-18Ni-8Cr alloy. The paper also reports on the evaluation of the free energy of formation of AlMgB14 using the thermochemical software program FactSage™.

Micro-Melt T15 Plus alloy is a high-speed powder metal tool steel. It may be considered for many types of tooling applications where either conventional or powder metal high-speed steels of either the M or T types are being used. This datasheet provides information on composition, physical properties, and hardness. It also includes information on wear resistance as well as forming, heat treating, and powder metal forms. Filing Code: TS-620. Producer or source: Carpenter Specialty Alloys.

Crucible CPM 420V is a unique tool steel made by the Crucible particle metallurgy (CPM) process. The alloy is designed from a martensitic stainless steel based analysis with added carbon and vanadium for exceptionally good wear resistance. CPM 420V offers significant improvements over CPM 440V in both wear and corrosion resistance. The exceptional wear resistance and good corrosion resistance of CPM 420V make it an excellent candidate to replace 440C and other corrosion- and wear-resistant materials, particularly where increased wear resistance is a primary concern. This datasheet provides information on composition, physical properties, hardness, and elasticity as well as fracture toughness. It also includes information on corrosion and wear resistance as well as heat treating and machining. Filing Code: SS-736. Producer or source: Crucible Service Centers.

Thirty-five species of nearshore, benthic ascidians were collected in Bermuda and notes were made on their habitat, microhabitat, susceptibility to epizoic recruitment, morphology, and acidity. Twenty-four ascidian species were later analyzed for vanadium and iron contents. Ten species had vanadium concentrations of over 100 ppm d. W. (dry weight); three species had vanadium concentrations of over 1000 ppm d. W. Iron contents were independent of vanadium contents. Thirteen species had acidic (pH 5 2 ) tunic fluids. Tunic fluid pH was not associated with vanadium contents. Vanadium content was not significantly associated with habitat, microhabitat, susceptibility to epizoic recruitment, or coloniality. Tunic acidity was significantly associated with habitat and lack of epibionts. No acidic species had macroscopic epibionts. Coloniality was significantly associated with lack of epibionts. These findings are discussed in reference to previous experimental work, which has shown that high vanadium contents and acidity are involved in chemical defense in ascidians, and in reference to the role of chemical defenses in sessile, epibenthic, marine invertebrates.

Manufacturing industries are presently using many tool materials, such as high speed steel, carbide tool and diamond tools etc. The most widely and commonly used tool in the engineering industries is high speed steel (HSS). The HSS tools are the cheapest and reliable for medium and small scale industries. In this work, the HSS single point cutting tool is taken as substrate material and coated with two different combinations of TiAlN composite coating using Physical vapour deposition (PVD) technique. Also, Tool life was calculated and compared with uncoated HSS tool. The hardness and surface roughness value for both the tools have been taken under same condition. The loss of weight in the tool after machining has been weighed using standard equipments. The differences have been closely observed with sufficient trials and find out the loss in weight in both the tools. The weight loss percentage was calculated after proper machining trials. The tool life of the Titanium Aluminium Nitride (Ti 70%, Al 25%) coated tool has been increased by 3.74 times than that of uncoated tool. The surface finish for TiAlN (Ti 70%, Al 25%) coating is better than the uncoated tool. The PVD coated tools having better performance comparing with uncoated HSS tool.

In recent years, deep cryogenic treatment (DCT) is getting increased attention in many tooling applications as a mean to improve tool performance. However, contradictory results are reported indicating improved as well as deteriorated wear resistance. The goal of this work was to investigate effect of DCT on wear properties of tool steel and how they change depending on the tool steel type, and hardness and fracture toughness obtained. Results show that steel composition considerably affects the way how cryogenic treatment changes steel properties. For low carbon tool steel toughness properties can be improved for up to 70% at only minor hardness drop, but are quite limited in the case of high-speed steel, while at high carbon content both hardness and toughness are deteriorated. In general, DCT was found to result in reduced abrasive wear resistance except for cases of combined hardness and fracture toughness improvement.

The aim of this study was to develop a new tool material, which combines the toughness of Hot-Work Steel (HWS) with the wear resistance of High-Speed Steel (HSS). This has been realised via powder metallurgy by blending HWS and HSS powders. The blend, which may contain up to 30 vol.% of high-speed steel powders (grain size 150 microns), is subjected to Hot Isostatic Pressing (HIP). This results in a microstructure that shows a double dispersion of coarse HSS clusters with dispersed small carbides (< 5 microns) in a martensitic HWS matrix without carbides. The new materials can be treated to produce hardness levels of between 40 and 60 HRC. The materials were examined with respect to their wear resistance and fracture toughness and the results obtained were correlated to the microstructure. It is shown that the wear rate of the double dispersed material decreases as the HSS content increases without causing a significant reduction in fracture toughness.

To mitigate the risk of vapor corrosion damage to the overflow mechanical parts, WC-based metal-ceramic coatings were applied to the surface of a 45-gauge steel substrate by supersonic air-assisted flame spraying (HVAF). The mechanical and wear-resistant qualities of the coating were identified by Vickers micro-hardness, ball-disc friction, and wear test, as well as optics, scanning electron, X-ray diffractometer, and white light interferometer systems. The findings demonstrate the layered structure of the WC-based coating, which is made up of the bonded phase and its distribution of hard phase particles that are diffusely dispersed. The coating is free of cracks, inclusions, and other defects, and its structure and organization are dense with a porosity of 0.86 ± 0.05%. The phenomenon of oxidative decarburization did not occur in the process of preparing the WC hard phase for WC-based metal-ceramic coatings. As a result, the coating’s micro-hardness of 11.83 ± 0.55 GPa is eight times that of the substrate. The results of comparing the three-dimensional abrasion patterns of the coating and the substrate reveal that the coating has superior abrasion resistance because its width and depth of abrasion are smaller than that of the substrate and a lot of furrows have formed on the substrate material’s surface. In contrast, the sprayed layer only had faint traces of abrasion. After three years of actual service, the impeller surface coating is essentially unaltered, which effectively addresses the issue of vapor corrosion damage to the slurry pump’s impeller and extends the pump’s service life to guarantee the overflow mechanical components operate safely and steadily.

Sepiolite: A new component suitable for 380 ​km/h high-speed rail brake pads