Ceramic knife

A ceramic knife is a knife with a ceramic blade typically made from zirconium dioxide (ZrO₂; also known as zirconia),^[1] rather than the steel used for most knives. Ceramic knife blades are usually produced through the dry-pressing and firing of powdered zirconia using solid-state sintering. The blades typically score 8.5 on the Mohs scale of mineral hardness, compared to 4.5 for normal steel and 7.5 to 8 for hardened steel ^{[citation needed]} and 10 for diamond. The resultant blade has a hard edge that stays sharp for much longer than conventional steel blades. However, the blade is brittle, subject to chipping, and will break rather than flex if twisted. The ceramic blade is sharpened by grinding the edges with a diamond-dust-coated grinding wheel.

Zirconium oxide

A ceramic knife made from blackened zirconia, super heated under pressure.

Zirconium oxide is used due to the fact it exists in several different forms. Zirconium can be monoclinic, tetragonal or cubic in form. Cooling to the monoclinic phase after sintering causes a large volume change, which often causes stress fractures in pure zirconia. Additives such as magnesia, calcia and yttria are used in manufacturing the knife material to stabilize the high-temperature phases and minimize this volume change. The highest strength and toughness is produced by the addition of 3 mol% yttrium oxide yielding partially stabilized zirconia. This material consists of a mixture of tetragonal and cubic phases with a bending strength of nearly 1,200 MPa (170,000 psi). Small cracks allow phase transformations to occur, which essentially close the cracks and prevent catastrophic failure, resulting in a relatively tough ceramic material, sometimes known as TTZ (transformation-toughened zirconia).

Properties

Ceramic knives are substantially harder than steel knives, will not corrode in harsh environments,^[2] are non-magnetic, and do not conduct electricity at room temperature. Because of their resistance to strong acid and caustic substances,^[3] and their ability to retain a cutting edge longer than steel knives,^[2] ceramic knives are suitable for slicing boneless meat, vegetables, fruit and bread. Since ceramics are brittle, blades may break if dropped on a hard surface, although improved manufacturing processes have reduced this risk. They are also unsuitable for chopping through hard foods such as bones or frozen foods, and for applications which require prying, which may cause breaking or chipping. Several brands offer either a black-coloured or a designed blade made through an additional hot isostatic pressing step, which increases toughness.

Sharpening and general care

A diamond dust sharpener with cradle for a ceramic knife.

Unlike a steel blade that benefits from regular honing and resharpening in order to keep a sharp edge, a much harder ceramic blade will stay sharp and retain its cutting edge for much longer—at least ten times longer according to tests on a particular knife.^[4] However, the hardness of the ceramic material also makes it difficult to resharpen.^[5] Consequently, although a ceramic knife does not need regular sharpening in the same way as steel, when its blade eventually becomes blunt or chips specialized sharpening services are required for the ceramic edge.^[6]

References

^ "Frequently Asked Questions | Ceramic Advantage | Ceramic Knives | Kyocera Advanced Ceramics". Archived from the original on 2015-12-10. Retrieved 2015-12-20.
^ ^a ^b The Ceramic Society of Japan (31 July 2012). "22.1 Ceramic Knife, Grater, Slicer and Scissors (first commercialised 1984)". In Yoshihiko Imanaka (ed.). Advanced Ceramic Technologies & Products. Springer Science & Business Media. pp. 529–530. doi:10.1007/978-4-431-54108-0_22. ISBN 978-4-431-53913-1. S2CID 136842009.
^ Wilson, Bee (22 Jun 2012). "At the cutting edge: ceramic knives". The Telegraph. Retrieved 27 July 2016.
^ "Kyocera catalog" (PDF). 6 April 2012. Archived from the original on 2015-10-13. According to the Cutlery and Allied Trades Research Association (CATRA), an independent testing organization, recent [November 2005] tests show that the life of a Kyocera ceramic blade without resharpening is approximately 10 times that of a typical steel blade.
^ Wolfgang Puck (8 April 2007). Wolfgang Puck Makes It Easy: Delicious Recipes for Your Home Kitchen. Thomas Nelson. pp. 269–. ISBN 978-1-4185-7093-4.
^ Sur La Table; Sarah Jay (21 October 2008). Knives Cooks Love: Selection. Care. Techniques. Recipes. Andrews McMeel Publishing. pp. 12–. ISBN 978-0-7407-7002-9.

External links

Media related to Ceramic knives at Wikimedia Commons

[1] "Frequently Asked Questions | Ceramic Advantage | Ceramic Knives | Kyocera Advanced Ceramics". Archived from the original on 2015-12-10. Retrieved 2015-12-20.

[Japan2012-2] The Ceramic Society of Japan (31 July 2012). "22.1 Ceramic Knife, Grater, Slicer and Scissors (first commercialised 1984)". In Yoshihiko Imanaka (ed.). Advanced Ceramic Technologies & Products. Springer Science & Business Media. pp. 529–530. doi:10.1007/978-4-431-54108-0_22. ISBN 978-4-431-53913-1. S2CID 136842009.

[3] Wilson, Bee (22 Jun 2012). "At the cutting edge: ceramic knives". The Telegraph. Retrieved 27 July 2016.

[4] "Kyocera catalog" (PDF). 6 April 2012. Archived from the original on 2015-10-13. According to the Cutlery and Allied Trades Research Association (CATRA), an independent testing organization, recent [November 2005] tests show that the life of a Kyocera ceramic blade without resharpening is approximately 10 times that of a typical steel blade.

[Puck2007-5] Wolfgang Puck (8 April 2007). Wolfgang Puck Makes It Easy: Delicious Recipes for Your Home Kitchen. Thomas Nelson. pp. 269–. ISBN 978-1-4185-7093-4.

[TableJay2008-6] Sur La Table; Sarah Jay (21 October 2008). Knives Cooks Love: Selection. Care. Techniques. Recipes. Andrews McMeel Publishing. pp. 12–. ISBN 978-0-7407-7002-9.

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v t e Knives and daggers
List of daggers List of blade materials
Kitchen and table knives	Boning Boti Bread knife Butcher knife Butter knife Caidao Cheese knife Chef's knife Cleaver Electric knife Fillet knife Grapefruit knife Lame Mezzaluna Parmesan knife Pizza cutter Splayd Steak knife Tomato knife Japanese kitchen knives Deba bōchō Maguro bōchō Nakiri bōchō Santoku Sashimi bōchō Udon kiri Unagisaki hōchō Usuba bōchō Yanagi ba
Other knives	Aircrew Survival Egress Knife Athame Balisong/Butterfly Ballistic Ballpoint pen knife Bayonet Boline Bolo Boot knife Bowie Cane knife Ceramic knife Clip point Combat knife Commander Corvo CQC-6 Deba bōchō Diving knife Drop point Fairbairn–Sykes fighting knife Gerber Mark II Ginsu Golok Gravity knife Guna Hacking knife Higonokami Hunting knife Husa knife Ivan's Knife Jacob's ladder Karambit Kard Kirpan Kitchen knife Kukri Laguiole knife Machete Mandau Marking knife Misericorde Mora knife Multi-tool Navaja Neck knife Nontron knife Opinel knife Palette knife Pantographic knife Parang Penknife Penny knife Pesh-kabz Pirah Pocketknife Phurba Putty knife Puukko Rampuri Resolza Sabatier Sami knife SARK Scalpel Seax Sgian dubh Sharpfinger Sheath knife Shiv Sliding knife Smatchet SOG Knife Straight razor Strider SMF Survival knife Swiss Army knife Switchblade Taping knife Throwing knife Trench knife Tumi Ulu Utility knife Verlängerungsmesser Warrior knife Wedung X-Acto Yarara Parachute Knife Yatagan
Daggers	Anelace Applegate–Fairbairn fighting knife Arkansas toothpick BC-41 Bagh nakh Balarao Baselard Bichuwa Bollock dagger Cinquedea Dha Dirk Ear dagger Emeici Facón French Nail Gunong Hunting dagger Jambiya Jile Kabutowari Kaiken Kalis Katar Khanjali Khanjar Kris Kunai Liaoning dagger Mark I trench knife Microtech Jagdkommando Parrying dagger Poignard Pugio Push dagger Rondel dagger Seme Shobo Sica Stiletto Tantō U.S. Marine Raider stiletto V-42 Yoroi-dōshi
Manufacturers	Aitor Knife Company Al Mar Knives American Tomahawk Company Aritsugu Benchmade Böker Buck Knives Camillus Cutlery Company Cattaraugus Cutlery Company Chris Reeve Knives Chroma Cnife Clauss Cutlery Company Cobray Company Cold Steel Columbia River Knife & Tool Cuisinart Cutco Dalian Hanwei Metal Dexter-Russell Ek Commando Knife Co. EKA Emerson Knives F. Dick Fällkniven FAMAE Fiskars Gerber Legendary Blades Füritechnics Glock Ges.m.b.H. Imperial Schrade Ivan's Ka-Bar Kershaw Knives KitchenAid Korin Japanese Trading Company Kyocera Leatherman Mad Dog Knives Marble Arms Medford Knife and Tool Microtech Knives Morseth Muela Murphy Knives OLFA Ontario Knife Company Opinel Randall Made Knives Ranz Cuchillos Rösle Sabatier Shun Cutlery Slice, Inc. SOG Specialty Knives Spyderco STI Knives Strider Knives Thiers Issard TOPS Knives Tramontina Victorinox W. R. Case & Sons Cutlery Co. Carl Walther GmbH Wenger Western Knife Company Wilkinson Sword Wüsthof Yoshida Metal Industry Global Zero Tolerance Knives Zwilling J. A. Henckels
Knifemakers	Rex Applegate James Black Tom Brown Jr. Blackie Collins John Nelson Cooper Jack W. Crain Ernest Emerson Jerry Fisk Bill Harsey Jr. Phill Hartsfield Gil Hibben Jimmy Lile Bob Loveless William F. Moran Ken Onion Ralph Osterhout Bo Randall Chris Reeve A. G. Russell Jody Samson William Scagel Mike Snody Robert Terzuola Michael Walker Buster Warenski Daniel Winkler
Associations	American Bladesmith Society Cutlery and Allied Trades Research Association Knifemakers' Guild
Category:Knives / Daggers