News
[Contact Us]
Tel: +86 (0)731 8972 3191
Fax: +86 (0)731 8972 3336
Mobile: +86 186 8497 3363
E-mail: santech@santechchem.com
Current position:Home >> News >> Industry News
Hot Pressing and Sintering 2015-08-25

Hot pressing
Hot pressing is a high-pressure, low-strain-rate powder metallurgy process for forming of a powder or powder compact at a temperature high enough to induce sintering and creep processes.This is achieved by the simultaneous application of heat and pressure.

Hot pressing is mainly used to fabricate hard and brittle materials. One large use is in the consolidation of diamond-metal composite cutting tools and technical ceramics. The densification works through particle rearrangement and plastic flow at the particle contacts. The loose powder or the pre-compacted part is in most of the cases filled to a graphite mould that allows induction or resistance heating up to temperatures of typically 2,400
℃  (4,350℉). Pressures of up to 50 MPa (7,300 psi) can be applied.other great use is in the pressing of different types of polymers.

This forming technique is the simultaneous application of external pressure and temperature to enhance densification. It is conducted by placing either powder or a compacted preform into a suitable die, typically graphite, and applying uniaxial pressure while the entire system is held at an elevated temperature, e.g. 2000℃ for SiC.

Hot Pressing is only suited to relatively simple shapes, with the components usually requiring diamond grinding to achieve the finished tolerances. 

Sintering 
Sintering is the process of compacting and forming a solid mass of material by heat and/or pressure without melting it to the point of liquefaction.
 
Control of temperature is very important to the sintering process, since grain-boundary diffusion and volume diffusion rely heavily upon temperature, the size and distribution of particles of the material, the materials composition, and often the sintering environment to be controlled.
 
Metals powder can be sintered. This applies especially to pure metals produced in vacuum which suffer no surface contamination. Sintering under atmospheric pressure requires the use of a protective gas, quite often endothermic gas. Sintering, with subsequent reworking, can produce a great range of material properties. Changes in density, alloying, or heat treatments can alter the physical characteristics of various products.



下一篇:Indium Tin Oxide (ITO) in Touch Screens
上一篇:LCD panel makers shift production to larger sizes
Copyright © 2013 Changsha Santech Materials Co.,Ltd. www.santechchem.cn