Internal Defects Of Die Castings
Stoma
(1) Features and inspection methods: Appearance inspection or flaw detection inspection after dissection, the pores have a smooth surface and a round shape.
(2) Reasons:
(3) Treatment method:
Shrinkage and porosity
(1) Features and inspection methods:
(2) Reasons:
(3) Treatment method:
Inclusions
(1) Features and inspection methods:
The metallic or non-metallic impurities mixed into the die-casting parts can be seen irregularly, dots or holes with different sizes, colors, and heights after processing.
(2) Reasons:
(3) Treatment method:
Use clean alloy material, especially the dirt on the recharge material must be cleaned;
2.4 Brittleness
(1) Features and inspection methods:
The crystal grains of the base metal of the casting are too large or very small, which makes the casting easy to break or break.
(2) Reasons:
(3) Treatment method:
2.5 Leakage
(1) Features and inspection methods:
Die-casting parts have undergone pressure test, resulting in air leakage and water seepage.
(2) Reasons:
(3) Treatment method:
2.6 Non-metallic hard points
(1) Features and inspection methods:
Mechanical processing or appearance inspection or metallographic inspection after machining found that there are small particles or lumps with higher hardness than the metal matrix on the casting, which makes the tool wear seriously, and often shows different brightness after cnc machining.
(2) Reasons:
(3) Treatment method:
2.7 Metal hard point
(1) Features and inspection methods:
The appearance inspection or metallographic inspection during mechanical processing or after CNC machining found that there are small particles or lumps with higher hardness than the metal matrix on the castings, which makes the tool wear serious, and often shows different brightness after cnc machining.
(2) Reasons:
(3) Treatment method:
The Influencing Factors Of Defects
3.1 Common defects and influencing factors of die castings
3.2 Ideas to solve defects
Since the causes of each type of defect come from multiple different influencing factors, it is necessary to solve the problem in actual production. In the face of many reasons, is it to adjust the machine first? Or repair the mold first? It is recommended to simplify according to the degree of difficulty. After complex processing, the sequence:
3.3 For example, the cause of flashing in die castings
