| 摘要 |
<p>A metal body or compact is made, contg. >=1 internal helical channel, starting from a cylindrical or conical core which is provided on its periphery with corresp. channel(s) or groove(s). The channel(s) are temporarily filled, and a layer of metal powder is compacted round the core, followed by sintering of the assembly and removal of the temporary filling(s). The core is pref. also formed from metal powder sintered with the outer layer, esp. using the same powder, and/or a tool steel powder for the outer layer. The temporary filling is pref. a resin, rubber, plastic; or wax removed at the start of sintering by melting or evapn. Used in the mfr. of e.g. a large borer which is provided with water cooling channels. The invention provides a simple and inexpensive method for making the channels.</p> |
