Special Material

Maybe a ceramic, but not your granny's best

OK, maybe you could give 'em a gentle whack...I mean they are dogs.
Del

you don't define "high temp" or "hard" in this context so I'm probably going for overkill here but Elgiloy and MP35N are two possibles. Tungsten is another. Waspalloy, Inconel X-750, Rene' are also some possibles. if you were more forthcoming on the application I might could help you more.

Material should withstand High temp in excess of 2000 deg c.

Hard like spring steel.

Impact resistant, so that it wont collapse by hammering.

Different materials are available but not with all these properties. If I get something even nearer to these specs, that will be great.

Ceramics are hard & high temp resistant but brittle.

Spring steel is hard & can withstand impact but melts around 1500 deg c.

still not enough information, what environment? there are a number of metals that can function at those temps but depending on the environment they may oxidize or carbourize quickly.

why do I get the feeling this is yet ANOTHER pulse jet valve question? doesn't ANYONE bother to look at prior posts first?

Inconel-800/601 which withstand High Temp & is Hard, It has many use Like Burner Nozzles, Furnace Material & comes in Many combination of High Nickel content

+ 60 % & higher Depend on end use

Type 301 has a good corrosion resistance due to a content of 17 % Chromium and 7 % Nickel. A high tensile strength is obtained by cold rolling. Compared to Alloy 1.4301 (AISI 304) a much higher tensile strength of more than 2000 N/mm² can be reached. Because of this, 1.4310 is suitable for stainless springs and parts of higher strength.

Grade 420 stainless steel is a higher carbon version of 410; like most non-stainless steels it can be hardened by heat treatment. It contains a minimum of 12 per cent chromium, just sufficient to give corrosion resistance properties. It has good ductility in the annealed condition but is capable of being hardened up to Rockwell Hardness 50HRC, the highest hardness of the 12 per cent chromium grades. Its best corrosion resistance is achieved when the metal is hardened and surface ground or polished.

We use Inconel X750 for spring elements in braze jigs which are cycled up to about 900°C.

Carbon Graphite Composites might be a good alternative depending on your application.

You have not defind high temperature use. If it is for burner and other zero expansion glass ceramic is currently material of choice up to 2000 oC.

If your need is to go only 300 to 500 oC than alloy 42, inconal or other materials will be a good coice.

All depends on your need