Method of manufacturing wick structure for heat pipe

Abstract

A method is disclosed to produce a wick structure for a heat pipe. The wick structure is a sintered powder wick and is produced by sintering process. A group of powders is firstly provided. The group of powders is then classified into many sub-groups in terms of powder size. At least one sub-group of the powders is selected to form the wick structure via the sintering process. Thus, the powders used to construct the wick structure are confined to powders having a relatively narrower range of powder size in relative to the group of powders as originally provided. This has greatly reduced the complexity involved in the sintering process, and as a result, the required sintering temperature and the required time for the sintering process are easier to be determined.

1 . A method of manufacturing a wick structure for a heat pipe comprising steps of: 
 providing a group of powders;    classifying the powders into multiple sub-groups in terms of powder size, the sub-groups having powder sizes different from each other;    selecting at least one sub-group of the powders; and    sintering the selected powders to form said wick structure.    
   
   
       2 . The method of  claim 1 , wherein the powders as provided are one of copper powders, nickel powders, stainless steel powders and ceramic powders.  
   
   
       3 . The method of  claim 1 , wherein the powders as provided are classified into the multiple sub-groups by passing through a series of screens.  
   
   
       4 . The method of  claim 1 , wherein, when more than one sub-groups of the powders are selected, the selected sub-groups of the powders are mixed in a prescribed ratio by weight.  
   
   
       5 . A method of manufacturing a wick structure for a heat pipe comprising steps of: 
 providing multiple groups of powders with each group having an average powder size different from that of each of the other groups;    selecting at least one group of powders from said multiple groups; and    sintering the selected powders to form said wick structure.    
   
   
       6 . The method of  claim 5 , further comprising a step of mixing the selected powders in a prescribed proportion by weight before sintering.  
   
   
       7 . The method of  claim 6 , wherein the multiple groups of powders are obtained by classification from an original group of powders having the multiple groups of powders.  
   
   
       8 . The method of  claim 7 , wherein the original group of powders is classified into the multiple groups of powders by passing through a series of screens.  
   
   
       9 . The method of  claim 7 , wherein the powders are ceramic powders.  
   
   
       10 . The method of  claim 7 , wherein the powders are one of copper powders, nickel powders and stainless steel powders.  
   
   
       11 . A method for forming a wick structure for a heat pipe, comprising: 
 preparing a group of powders;    separating the group of powders into a plurality of sub-groups of powders according to a size distribution of the powders, the sub-groups occupying different regions of the size distribution, respectively; 
 selecting at least one of the sub-groups of powders and filling the selected powders into a casing of the heat pipe; and  
 heating the casing and the selected powders to sinter the selected powders in the casing to thereby obtain the wick structure in the casing of the heat pipe.  
   
   
   
       12 . The method of  claim 11 , wherein two sub-groups of powders are selected, size ranges of the selected two sub-groups of powders are at discontinuous regions of the size distribution of the powders.  
   
   
       13 . The method of  claim 11 , wherein the size distribution is a normal distribution, and one sub-group of powders is selected which includes a median of the normal distribution.  
   
   
       14 . The method of  claim 12 , wherein a heating temperature and period of time for the heating step are selected to melt the selected powders of one of the two sub-groups substantially entirely, which have a smaller powder size than the selected powders of the other of the two sub-groups.  
   
   
       15 . The method of  claim 12 , wherein one of the two sub-groups, which has a smaller powder size has a weight less than that of the other of the two sub-groups, which has a larger powder size.  
   
   
       16 . The method of  claim 15 , wherein the other of the two sub-groups, which has the larger powder size has a weight which is five to twenty times of that of the one of the two sub-groups, which has the smaller powder size.