Method for Manufacturing High Strength Ultra-Fine/Nano-Structured Al/Aln or Al Alloy/Aln Composite Materials

Abstract

The present invention relates to the a method for manufacturing high strength ultra-fine/nano-structured aluminum/aluminum nitride or aluminum alloy/aluminum nitride composites using mechanical milling or mechanical alloying process which is conducted in the nitride-forming atmosphere such as nitrogen gas (N), ammonia gas (NH) or mixed gas including both gases, subsequent heat treatment process, and hot consolidation process. Also, high strength ultra-fine/nano-structured Al/ALN or Al alloy/ALN composite materials fabricated by the method of present invention have superior mechanical strength and heat resistance to those fabricated by conventional powder metallurgy process or liquid processes.

1 . Method for manufacturing high strength ultra-fine nano-structured aluminum and aluminum nitride or aluminum alloy and aluminum nitride composite materials, wherein aluminum powder or mixture powder of the aluminum and alloying element is mechanically milled and mechanically alloyed in an atmosphere of NH 3  gas containing nitrogen for inducing nitrification reaction so as to produce a precursor of aluminum nitride; subsequent heat treatment is performed to produce aluminum and aluminum nitride or aluminum alloy and aluminum nitride composite powder; this composite powder is subjected to a hot forming process to produce composite material. 
   
   
       2 . The method of  claim 1 , wherein the mechanical milling and mechanical alloying are performed in a vessel in which the atmosphere of NH 3  gas containing is maintained. 
   
   
       3 . The method of  claim 1 , wherein the subsequent heat treatment for production of aluminum nitride is performed at a temperature of 400° C. to the melting temperature of the composite powder for 0.1˜48 hours. 
   
   
       4 . The method of  claim 1 , wherein the subsequent heat treatment in the hot forming process is a high-temperature degassing process. 
   
   
       5 . The method of  claim 1 , wherein the grains of aluminum or aluminum alloy matrix and the aluminum nitride reinforcement particles have a ultra-fine nano-structure with a size equal to 10 μm or less through the mechanical milling or mechanical alloying process. 
   
   
       6 . The method of  claim 1 , wherein to aluminum matrix, solid solution hardening elements like magnesium, silver and manganese could be added in the range of 0.1 wt. % to solubility limit, precipitation hardening elements like copper, zinc, silicon, titanium, iron, lithium, tin, chromium and zirconium could added with solubility limit or above, rare earth elements like yttrium, cerium, lanthanum, scandium, samarium, neodymium, gadolinium, praseodymium and misch metal could be added in the range of 0.1 wt. % to 10.0 wt. %, alloying elements like tungsten, molybdenum and cobalt could be added in the range of 0.1 wt. % to 50.0 wt. % or ceramic reinforcement particles like Al 2 O 3 , SiC and Si 3 N 4  could be added in the range of 0.1 wt. % to 50.0 wt. %.