One of the services my department provides to our customers is "Defect Analysis". And this is one of the most frequently used. In fact, customers that have used this service continue to request it over and over again.
There are many consultants in the die casting industry today. Most of whom have many years of hands on experience, and they offer valuable services using techniques they learned over the years. However, Eastern Alloys is one of the only companies which also use metallurgical techniques when analyzing defects. This type of service requires:

• An understanding of the die casting process
• A knowledge of die casting defects
• Training how to use metallurgical techniques when diagnosing defects.

To offer this free service, Eastern Alloys has always staffed Metallurgical Engineers who understand the die casting process, and are trained at analyzing die casting defects.
 
Some defects can be solved by examining the hydraulics of the die casting machine, using shot traces, examining how molten metal flows through the runner system, or measuring process parameters such as die temperature, lubrication amounts, etc…. These are techniques that should be used by all die casters; however, uncovering the real cause of defects often requires a closer look, using metallurgical techniques.  
 
Below are two examples where a "closer look" was required, resulting in a correct analysis and subsequent "fix". 

Figure 1
Part Design:  Often defects are caused by poor design. In this instance, a zinc die cast rivet was cracking during use. The die casting machine appeared to be running optimally, and a general observation showed that the casting was of good quality. After using metallurgical techniques to examine the casting at a microscopic level, a small shrinkage crack was found at the location of a sharp corner which happened to be the same area where the cracking occurred. A radius was added to eliminate the sharp corner causing the shrinkage crack, and the defect was eliminated.

Figure 2

Plating Defects:  It is difficult to analyze plating defects, and often disagreements occur between the electroplater and die caster regarding the cause of the defect.  This particular instance showed that the fine surface defects appeared only in the plating layer, and did not have any associated die casting defects.  Using metallurgical techniques provided the required information and data necessary to find the real cause of defects, and helped stop the disagreements over the hypothetical possibilities.