Vol. 12
September Issue
Year 2011

Cover Page

in Vol. 12 - September Issue - Year 2011
Manufacturing Blast Nozzles for More Than 50 years


Chart 1: A comparison of the hardness of different ceramic materials and hard metal (tungsten carbide)

Chart 2: The hardness is not the only characteristic for a good wear resistance

Chart 3: The lifetime of boron carbide nozzles with different blasting media

 In the Spotlight

ESK Ceramics GmbH & Co. KG is one of the world’s leading manufacturers of advanced ceramic products and materials for industrial applications, and a specialist in the field of nickel dispersion coatings. Our extensive range of materials comprises borides, carbides and nitrides, for example boron carbide, boron nitride, silicon carbide, silicon nitride and titanium diboride. Furthermore, ESK is continually developing new applications for ceramic materials in cooperation with customers and research institutes. The company was founded in 1922 and now employs over 620 people in Kempten (Allgäu/South Germany). Since 2004, ESK has been a wholly owned subsidiary of Ceradyne Inc., which is based in Costa Mesa, California (USA) and publicly listed on the US NASDAQ technology stock exchange. Ceradyne has over 2,067 employees at a total of 16 sites worldwide. Its sales in 2010 reached USD 403 million. As globally successful manufacturers of technical high-performance ceramics, Ceradyne and ESK are ideal partners, unleashing synergies to the benefit of customers.

First-Class Quality TETRABOR® Boron Carbide Blasting Nozzles from ESK.

As the world leader in high performance ceramics, ESK has been producing boron carbide blast nozzles for more than 50 years. During this time they have steadily expanded their blast nozzle portfolio and offer TETRABOR® nozzles of first-class quality manufactured by first-class technology.

Blast nozzles together with different blasting media are used for:
• surface preparation for a coating or bonding process
• surface cleaning and finishing, like deburring or removing production contaminants
• shot peening to increase the strength and durability of high-stress components

This technology is used for:
• modeling in the dental industry
• engraving in the glass industry
• cleaning in the building and construction industries
• deburring and descaling in the foundry and steel industries
• strengthening parts in the automotive and aviation industries

Blast Nozzles Manufacturing

ESK developed a high quality powder which is conditioned so as to make it effective for the different manufacturing steps of Boron Carbide blast nozzles. This special powder is the key for the exceptional quality of TETRABOR® nozzles. Depending on the part size and the order quantity one of the following three forming methods is used:
• Cold isostatic pressing (for large parts and small quantities)
• Dry isostatic pressing (medium and large quantities)
• Axial die pressing (large quantities)
After the forming process, the so-called "green part" (compressed powder with a binder system) is machined to get a nozzle near net shape. Following debinding, pressureless sintering and hot isostatic pressing, the nozzle is a dense boron carbide ceramic part with the required material characteristics. Dimensions with tight tolerances have to be hard-machined with diamond-coated grinding wheels. After quality control, the boron carbide insert is sold directly or as a blast nozzle with a steel or aluminum jacket.

Blast Nozzles

ESK TETRABOR® boron carbide blast nozzles have the best price performance in combination with all blasting agents, from glass beads through steel grit to silicon carbide. Boron carbide is one of the hardest engineering materials available and therefore offers extreme abrasion resistance.
Chart 1 shows a comparison of the hardness of different ceramic materials and hard metals (tungsten carbide).

TETRABOR® Boron Carbide shows the best value, followed by silicon carbide. The value for tungsten carbide is at the lower end of the range.

The fact that the hardness is not the only criterion for the nozzles’ performance is shown by Chart 2. It presents a test comparison of Venturi nozzles with an inner diameter of 8 mm and a length of 100 mm made of aluminum oxide, silicon nitride, tungsten carbide, silicon nitride and TETRABOR® boron carbide. The wear of all 5 nozzles was tested at a blasting pressure of 6 bars and with aluminum oxide as blasting medium (grain size 1 mm, flow rate of 300 kg/h).

Chart 2 shows clearly, that the hardness is not the only characteristic for a good wear resistance. The tungsten carbide nozzles show a much better performance compared to the hardness. The same applies to the TETRABOR® boron carbide nozzle. The result of the wear resistance exceeds the hardness and is outstanding compared to all the other materials tested.

The lifetime of TETRABOR® nozzles depends heavily on the blasting medium. Chart 3 shows the lifetime of boron carbide nozzles with different blasting media.

ESK blast nozzles offer the following clear advantages also taking into account the air and blasting media consumption and the downtime for exchanging the used nozzle:
• By far the best price performance ratio
• Low air consumption through minimal widening of the bore
• Constant operation conditions and uniform blasting performance
• Easy handling through low weight (density = 2.5 g/cm3)

Since the middle of this year, ESK  offers an updated portfolio of standard nozzles and (new!) TETRABOR® standard inserts together with nozzle holders and adaptors. A catalog is available at www.esk.com. These items are always in stock, and orders can be shipped immediately. As a special service for OEMs, they also offer to engineer and manufacture customized nozzles and inserts.

Beginning 2011, ESK has also established a new shipment-quantity-based rebate system, which offers very attractive prices for OEMs and large distributors. For more details, please see their new catalog, which is available at www.esk.com.

Boron carbide blast nozzles guarantee minimum wear and have an exceptionally long service life even in applications requiring extremely hard abrasives. They are the first choice for heavy-duty blasting technologies. Today, ESK, with its TETRABOR® nozzles and inserts, is the market leader in Europe. With new portfolio of nozzles and inserts, in combination with new rebate system, they will expand their business to Asia and America.

Author: Gerd Weisel, Senior Sales Manager
For Information:
ESK Ceramics GmbH & Co. KG
Max-Schaidhauf-Straße 25
87437 Kempten, Germany
Tel. +49.831.5618.119
Fax +49.831.5618.8119
E-mail: GWeisel@esk.com