Powder metallurgy technology at the service of diamond-impregnated tool production

ABSTRACT

Different approaches to take advantage of powder metallurgy in the manufacturing of diamond-impregnated components were studied. Three different powders were used as starting materials; two pre-alloyed powders, based on Fe–Cu and Fe–Cu–Sn systems, and one pre-mixed Fe-based powder. Different manufacturing routes as a strategy to obtain tailored mechanical properties were studied, with the influence of alloying elements such as graphite, iron phosphide and Mn–Ni–B master alloy to reinforce the iron-based powders. Both uncoated and coated commercial synthetic diamonds were introduced in the systems to analyse the surface reactions that depend on both metallic matrix and processing parameters. Hardness values from 88 to 105 HRB were obtained with a wide range of transverse rupture strength values from 1250 to 1640 MPa. An appropriate combination of metallic matrix, alloying elements and processing parameters makes the materials analysed here suitable powders for the manufacturing of diamond-impregnated tools.

KEYWORDS:

• Diamond-impregnated tool
• pre-alloyed powders
• hot pressing
• free sintering
• infiltration
• metallic matrix
• alloying elements
• synthetic diamond

Acknowledgements

The authors wish to thank W. Diamant Herramientas for the financial support of this work.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

C. Luno-Bilbao

C. Luno-Bilbao: Doctor of Science expert in powder metallurgy. More than 10 years of experience in the design and development of metal matrix for diamond tool production. Her work is focused on the design of metallic powders (atomized with gas, water, premixed) that give rise to metallic phases compatible with the stability of diamond at sintering temperatures. She is a main researcher in Ceit's Advanced Manufacturing and Powder Metallurgy Group in the field of diamond tools, taking responsibility for projects in this field, developing new projects, supervising work teams and serving as an interlocutor with clients.

N.G. Polvorosa

N. G. Polvorosa: PhD in materials science and engineering from 2019. Expert in powder metallurgy focus on hard materials and the development of metallic matrixes for diamond tools. Her work is focused on the design of metallic powders that give rise to metallic phases compatible with the stability of diamond at sintering temperatures.

G. Peña

G. Peña: Expert in powder metallurgy and diamond tools, laboratory and equipments. Currently, he is R&D technician at Ceit's Advanced Manufacturing and Powder Metallurgy Group.

A. Fayanas

A. Fayanas: Researcher at Ceit's Advanced Manufacturing and Powder Metallurgy Group focused on the study of bonds for diamond tools and development of powders for binder jetting technology.

J. Perez

J. Perez: Researcher at Ceit's Advanced Manufacturing and Powder Metallurgy Group focused on the development of bonds for diamond impregnated tools and the study of the stability of the diamonds during the manufacturing process.

I. Guruceaga

I. Guruceaga: Researcher at Ceit's Advanced Manufacturing and Powder Metallurgy Group focused on the study of bonds for diamond tools and development of powders for binder jetting technology.

A. Veiga

A. Veiga: PhD in materials science and engineering from 2015. An expert in physical metallurgy, she is currently researching the applications of a laser multifunction cell both in additive manufacturing by LMD, as remote laser welding and laser heat treatments.

I. Iturriza

I. Iturriza: Head of the Advanced Manufacturing on Powder metallurgy and Laser Group since February 2016. He has participated in more than 50 research projects, being the principal investigator in more than 30. Strong research activity in the design, atomization, sintering, heat treatments and applications of tool steels. He is pioneer in the design of compositions and computer-aided processes. Responsible for Hot Isostatic Pressing (HIP). Pioneer in the introduction of this technology in the manufacture of diamond tools and composite materials with a high concentration of superabrasives. Encapsulation in glass, encapsulation with metallic materials. Hybrid sinter-HIP processes, HIP additive technologies, microfusion-HIP, near net shape … applied to aeronautical sectors, energy, automotive, defense, chip removal, stone processing, civil engineering. He participated in the foundation and start-up of a spin-off dedicated to the industrial atomization of powders. Head of the Materials and Division at Ceit.