How to select insert alloy for drilling application
The materials used to make drill bits and cutting inserts play a crucial role in the performance of these components. There are several hard and tough material options, ranging from cemented tungsten carbide, ceramic, boron nitride or diamond.
Carbide and Ceramic:
Coated carbide inserts are a good choice for working with ferrous materials such as iron, cast iron, steel or stainless steel. They offer high levels of wear resistance and are widely used in turning operations.
Ceramic:
Depending on the type of machining application, ceramic inserts can be coated using chemical vapor deposition (CVD) or physical vapor deposition (PVD). Both processes produce thick coatings that are highly wear resistant and durable.
Indexable:
Indexable inserts are also available in a variety of geometry and grade to suit particular machining requirements. They provide a significant advantage over other insert types. If the cutting edge of an insert wears, it can simply be turned over to the unused side of the tool for continued production.
Tough Metal:
Soft, gummy, low-carbon steels such as mild and medium steel are problematic for machining because they can form long, troublesome chips. Chip control is achieved through feed rate, depth of cut and selection of insert geometry.
A conventional silver-based braze alloy, BAg-7, has been adapted to lower its braze temperature and increase its braze strength by adding one or more elements selected from the group of gallium (Ga), indium (In), and thallium (Tl). These alloying elements are added in any combination totaling between about 0.5% and about 10% by weight.