The pressed components need to be sintered at temperatures of up to 1350oC in a range of atmospheres in order to achieve the required properties. The firing temperature varies according to the metal powder being used, with iron based components being fired between 1050 – 1250oC for 20 – 30 minutes, bronze based components between 750 – 1050oC for 15-30 minutes, and vacuum-sintered stainless / high-speed steel components reaching 1250 – 1350 oC for a period of around 60 minutes. Most powdered metal components need to be fired in a protective atmosphere to prevent oxidation or reduction of the metal oxide during sintering, or to maintain or increase certain chemical properties. A range of atmospheres are used, including oxidising, reducing, inert / neutral, carburizing and nitriding. The atmosphere used depends on the material of the component, with more than one type sometimes being used a different stages of the sintering process. Most powdered metal sintering kilns use electric heating elements and can be split into two main categories: Continuous firing and intermittent kilns, the former being one of three different styles: Pedrail, walking beam or handspike, and the latter consisting of hot-press bell kilns and vacuum-sintering kilns (vacuum graphite tube kiln and intermediate frequency inducing kiln).
The usage temperature for kiln furniture is usually not very high (<1350 oC), but the kiln furniture must be able to withstand different atmospheres and rapid changes in temperature, therefore the material used is different to those used for normal ceramics customers. To meet the special requirements. These materials have excellent thermal shock resistance and can be used in different atmospheres without the powdered metal components sticking to the batts. Powdered metal components for the automotive industry in USA and Canada already successfully use these products.
|Kiln Furniture System||Main Kiln Furniture||Materials|
|Continuous kilns||Plain Batts（Full Discs Half Discs）|
|Intermittent kilns||Plain Batts（Full Discs Half Discs）|
Note：We do not recommend using cordierite-mullite Kiln furniture in a reducing atmosphere at temperatures above 1300 oC.