There are many factors to consider when choosing a pump. Not the least of which is what the individual components will be made from and any type of coatings or heat treating applications that should be applied. Over time these options have become industry standards and generally recognized as being most applicable to a specific downhole environment.
For example, barrels may be internally chrome plated for optimal performance in wells that must pump a lot of solid material, sand in particular. However, you would not want to use a chrome plated barrel if you are going to be acidizing the well, as the acid will strip the chrome out of the pump. In this scenario you may be better off using a barrel with a nickel-carbide coating, or even no coating.
Digging through text books and metallurgy research papers
would allow a person to piece together some of this information, however there have been no definitive tests or threshold levels established for the various options available. A person with experience and knowledge in this area will be able to recommend the most appropriate material options to maximize the life of the pump.
In an effort to make this range of options easier to understand, we have grouped categories of pump components and rated their available options against one another on critical factors. Although each factor can be further analyzed, this is the starting point for all material choices.