Diamante A&T Contents Year XXX - December 2024 |
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Front Cover: NADECO The National Association for Demolition and Circular Economy in Construction brings together the leading Italian companies operating in the deconstruction supply chain and serves as a reference point for this rapidly growing sector of the construction industry.
In the Spotlight 10) Tolerances and limits for drilling and diamond cutting in construction by Valeriano ParizziCutting Commission Coordinator, NADECO
Abstract: In the construction sector, precision in cutting and drilling concrete is essential to ensure the stability and safety of
structures. The National Association for Demolition and Circular Economy for Construction (NADECO) has published a technical document that defines the tolerances and limits
for cutting and core drilling operations with diamond wire. This article illustrates the key points of the document, providing practical guidance for engineers and technicians in the
sector. Tolerances in cutting and drilling concrete are crucial for several reasons: Diamond Tools 23) Comparative study of FAST and conventional sintering of cutting tool material by M.H. Rajaei1, A. Molinari1, I. Agote2, M.Á. Lagos2, D. Ferrari3, M. Dai Pré41 Department of Industrial Engineering, University of Trento, Italy 2 Tecnalia, Basque Research and Technology Alliance (BRTA), Donostia-San Sebastián, Spain 3 Dellas Spa, Lugo di Grezzana (VR), Italy 4 Plumake, Grezzana (VR), Italy
Abstract: This study explores the effectiveness of Field Assisted Sintering Technology (FAST) in producing cutting tools using a
Bronze 90/10, Co, Fe and W powder mix in granulated and non-granulated conditions. The goal is to evaluate and demonstrate FAST efficiency by comparing results obtained on the same system using a conventional
sintering approach. For the characterization of the samples, a Rietveld refinement XRD patterns combined with microstructural analysis, based on SEM and EDXS, was
considered. The study revealed that the sintering process significantly influenced microstructural characteristics. The FAST process, known for rapid heating and short sintering
periods, maintained a consistent ratio of starting phases, unlike conventional sintering prone to reactions, diffusion and intermetallic compound formation.
Conventional sintering resulted in cobalt polymorphs also exhibited a lattice expansion with respect to the starting powder, resulting mainly from the atomic rearrangement during
prolonged sintering process. FAST samples showed a lower volume change, due to short sintering time...
35) Processing Invar-Nb alloys by high energy ball milling for good diamond retention
Abstract: Diamond tools used to slab ornamental stones are composites made of diamond particles embedded into a bonding matrix.
These composites are normally manufactured by powder metallurgy. This paper deals with the development of a new alloy to adhere diamonds (bonding matrix).
In this sense, mechanical alloying (MA) was used to produce powders of Invar alloy (Fe-36%wt Ni) with Nb additions (5- 10-15% wt). MA experiments employed different milling times:
1/2.5/5/10/20 h, using the ball to powder ratio of 10:1. Powders' morphologies and sizes were studied by scanning electron microscopy (SEM), diffusion study were performed
by EDS coupled to the SEM, x-ray diffraction was used to evaluate the diffusion and solid solution formation. Scherrer's equation was employed to determine the mean
crystallites size; the lattice's micro-strain was calculated trough proposed equation by the works of Nekouei and Maia; particles' sizes distribution and mean particle size were also
determined. The results have shown that 15%wt Nb addition with 10 h ofmilling time generated better homogeneity, improved distribution and average particle size, along with complete
solid solution formation...
47) Polycrystalline diamond cutters with cobalt-rhenium binder for enhanced thermal stability in rock cutting
Abstract: The excellent abrasion resistance and impact resistance of polycrystalline diamond (PCD) make it the material of choice
for certain rock cutting applications. For example, a PCD table bonded to a WC/Co substrate forms a cutter suitable for oil and gas drilling. However, the presence of binder in
the PCD - infiltrated from the substrate during high pressure, high temperature (HPHT) sintering - severely shortens tool life through thermal degradation mechanisms.
Acid leaching this binder from the cutting surface significantly improves its thermal stability, but the use of alternative, more thermally stable binders is also an option.
In this work, a novel Co-Re binder was evaluated for thermally stable PCD. Hot-stage XRD confirmed a 200°C delay to the onset of graphitisation in the PCD compared to standard Co
binder-based PCD and post-heat treatment crack analysis demonstrated the suitability of this material for thermally demanding drilling applications...
58) Through sculpture, a journey full of charm, creativity and self-dicovery
Stone is a material that appears in as many varieties as the landscapes it comes from. Each stone brings with itself the geological history of the
planet, a memory that becomes color, shape, sound and even smell when you cut it. Each region is characterized by the historical use of what nature offers at a local level. Around each quarry, the stone is found everywhere
and becomes part of the collective identity of that region. I remember my astonishment in Galicia when I saw vineyards stakes made of granite! For this reason I always find interesting to deal with materials
new to me in their original environment: this allows me to create sculptures that work in harmony with the environment and the urban fabric creating no
fractures but rather a smooth transition. The discovery of stone materials through sculpture is a fascinating journey. The shining marble crystals, their transparency surpassed by onyx, the slate settling that reminds of the pages of a book, the infinite surprises hidden in
fossil limestone. For time immemorial we have been using stone; such as pumice containers to filter and keep fresh the scarce rainwater in the Canary
Islands, stone as a source of inspiration for a "Destiladera of thought" that became part of the Gernot Huber Foundation's Park collection in Tenerife in 2019.
64) 58th Marmomac attracted more than 50,000 operators from 140 countries confirming its leading role in the sector on a global scale
70) The international meeting point of the natural stone sector: Marble Izmir Fair is 30 years old
72) Join global players for a big celebration at Xiamen Stone Fair 2025
74) UCIMU-Sistemi per Produrre: in 2024 a sharp fall for the Italian machine tool industry. Growth at modest pace in 2025 |
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