August Hohhot - Colored Heavy Powder Standards Committee - Conference Report

From August 26th to 29th, 2010, the National Nonferrous Metals Standardization Technical Committee held a non-ferrous metal standard working conference in Hohhot, attended by nearly 100 representatives from more than 50 units across the country.
The Secretary General of the National Nonferrous Metals Standardization Technical Committee summarized the main work done by the Non-ferrous Standards Committee during the 11th Five-Year Plan period. The key work during the 12th Five-Year Plan period will focus on safety production, clean production, new materials and international standards.
The meeting discussed and validated 60 standards for non-ferrous metal products and analytical methods for "Conductive Copper and Copper Alloy Profiles" and "Cobalt Chemical Analysis Methods".


Cermic Ball Bearing

The full ceramic ball bearings listed below are supplied with rings and balls made from zirconium dioxide (ZrO2). These zirconia bearings are available as full complement (no cage) or with cages made from PTFE, PEEK or 316 stainless steel.

These are non magnetic, non-conductive and highly corrosion resistant to most chemicals although ZrO2 bearings are not recommended for prolonged contact with steam. Full complement bearings or those with a 316 stainless cage can be used up to 400°C while bearings with a PEEK or PTFE cage can cope with temperatures of up to 250°C. For temperatures below -70°C, PTFE or 316 stainless steel cages are preferred. Standard radial clearance for full ceramic bearings is C0 but other clearances can be supplied to order.

ZrO2 ceramic bearings are generally used for their extreme temperature capabilities, excellent corrosion resistance or non-magnetic properties. Other sizes can be supplied on request.Ceramic Bearing

Ceramic Bearing

The Description of Ceramic Bearings:



Compared to steel, Ceramic ball Bearings have many specific advantages. They offer superior corrosion and heat resistance, higher dimensional stability, and lower density, which facilitate high speed. Ceramics are superior to steel in heat and corrosion resistance, and are lightweight and extremely hard as well. Consequently, ceramic rolling bearings can be used in environments where conventional steel bearings cannot. That is to say, the superiority of these bearings makes it possible that they can be applied in some special environments.

Firstly, they can be used in corrosive environments. Compared to stainless steel bearings, hybrid and all Ceramic Bearing lasted three and twenty times longer respectively. It is presumed that water readily adheres to silicon nitride and forms a better lubrication film, leading to extended bearing life.

Secondly, they can be performed in corrosive agents. Generally, silicon nitride has excellent corrosion resistance. However, corrosion resistance varies depending on the type and quantity of sintering additives, and certain corrosive agents decrease in hardness and flexural strength. In such situation, it is can be proved that the carbide-based ceramic bearings are the most effective.

Thirdly, they can be used in high-temperature vacuum. An all-silicon nitride Ball Bearing with a self-lubricating laminated cage (mainly composed of MoS2) and with MoS2-coated rings and balls proved superior in durability in a high-temperature vacuum environment. Compared with the hybrid bearings, the all-ceramic bearing was superior in both dynamic frictional torque and life.

Fourthly, they can be performed with poor lubrication. As ceramics are extremely hard and have outstanding wear resistance, they outperform other materials in bearing life without lubrication. According to a test, the steel bearing seized within a short period while the hybrid and all 627 Ceramic Bearings, though sustaining wear, did not. And the all-ceramic bearing sustained considerably less wear than the hybrid bearing, indicating that its endurance life is much longer.

Cermic Ball Bearing,Full Ceramic Bearing,Hybrid Ceramic Bearing,Self-Aligning Full Ceramic Ball Bearing

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