镁合金压铸件化成后表面白斑形成机理
The Forming Mechanism of the White Spot on the Chemical Conversion Coating of the Die-Casting Magnesium Alloy
                  
              
    
                  
                    
                    摘要: 
	本文研究了镁合金压铸件化成处理后表面白斑形成机理,对其形态和组织进行了SEM及金相显微观察,并对其表面进行了粗糙度分析试验。结果表明:异型大块α相是白斑形成的主要原因,而白斑出现的本质是在压铸过程中,由于模具表面温度不一致,使得铸件表面形成粗大的先析α相,改变喷涂离型剂方法可消除此种不良现象。
                 
              
                
                    Abstract: The forming mechanism of the white spot of the die-casting magnesium was investigated by means of SEM andOM.The roughness of the white spot was also tested. It indicated that the larger α phase caused by the uneven temperature distribution of the die result in the formation of the white spot. It can be improved by changing the agent spaying parameter.
                
                   
                  
    
  
 
     
    
    
                
         
                
                
                 
                
                    
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