Application cases of end mills in the processing of medical device parts

There are numerous application cases of end mills in the processing of medical device parts. The following is an explanation based on different types of medical device parts and the advantages of end mills:

Processing of orthopedic implants

Case: In the production of orthopedic implants, the Jabro® series of solid end mills dedicated to Sankor Tools has played a significant role. Take the tibial bracket as an example. It is a knee joint implant product and is usually made of titanium alloy. For the production of such parts, the use of this series of four-piece tool sets can ensure successful processing. Among them, JH770 has stable performance and is capable of achieving rough machining applications close to the final size. JH710 is used for fine processing of side walls; The JH740 polishing edge tool can produce a perfect surface finish on the bottom surface of the bracket, which is one of the most important features of this type of implant. In addition, these brackets usually also have a knee pad locking function, and the JH790 included in the solution can meet this requirement. For titanium alloy components such as femoral implants, the multi-edge JH730 can quickly complete corner milling of the inner wall and perform finishing of the outer edge, while the highly stable JHP994 (an update of JHP992) has been optimized for rough machining of the inner wall. The JH780 conical ball head (TBN) tool is highly suitable for five-axis motion machining within the inner wall. The JH721 ball-end milling cutter can perform precise finishing operations, easily achieving high-quality inner wall connection surfaces. The flexible JH722 features specific material grades, grooves and coatings, making it suitable for multiple 2.5D and 3D semi-finishing and finishing tool paths.

Advantages: This series of cutting tools features slot profiles optimized for specific operations. The optimized HXT coating offers excellent performance and reliability in ISO-S and ISO-M materials. The shorter cutting edge length provides additional stability, strength, and cost-effectiveness for the shallow component characteristics commonly found in orthopedic parts.

Bone nail processing

Case: Bone screws are one of the most common orthopedic implants. Due to the need for good mechanical strength and biocompatibility, most bone screws are made of stainless steel or titanium alloy and adopt different thread designs, pitches and thread lengths. Although the structure of bone screws seems simple, their design is extremely complex. To address this challenge, precision CNC Swiss machining is typically employed to complete designs that provide appropriate features and functions for the final use of bone nails. In the processing of bone nails, Taikeluo provides a complete processing solution. For the external circle turning process, MiniForceTurn turning tools and AH8000 series material inserts are adopted. The AH8015 PVD-coated alloy material series is the preferred material. A high-aluminum content AlTiN nano-composite coating is used, which strikes a good balance between wear resistance and anti-chipping toughness. It is specially developed for difficult-to-machine materials. In the thread turning process, TetraForce-Cut (non-standard thread insert) is adopted. Its firm and safe insert locking ensures the reliability of the tool. The economical four-tip insert is used for slotting, cutting or thread processing. The unused tip during processing is protected to ensure that all four tips are fully available. Non-standard custom blades suitable for various slot and thread shapes can be selected. The firm blade locking enhances the reliability of the tool. The double rake face blade design can improve chip control and chip removal.

Processing of hip joint implants

Case: For parts like hip joint implants, the materials are mostly titanium alloys. During processing, 3M™ 726A soft cloth-based abrasive belts can be used for manual grinding or robot automated grinding. The equipment selected is a floor-standing abrasive belt machine. The ground products are available in different specifications such as 726A 80+, 180+, 240+/320+, and 400+. Meanwhile, the linear speed of the abrasive belt should be controlled at 10-18m/s (made of titanium alloy).

Bone plate processing

Case: In the processing of bone plates, Changhe Industry has launched end mills suitable for titanium alloy processing. This tool features an ultra-high-temperature resistant coating and a special rake Angle design that can suppress burrs, enabling stable and long-life milling operations. For instance, when processing bone plates made of TC4 material, using a CNC machining center and this type of tool (such as D4XR0.5X8XD4X50LX4T), the chip removal of the processing holes is smooth, the surface quality of the side walls is good, and the tool life is comparable to that of other imported brands.

Processing of femoral knee joint replacement components

Case: The femoral knee joint replacement component imitates the natural shape of the joint and is usually made of cobalt-chromium-molybdenum and 17-4 PH stainless steel. The surface processing of the femoral condyle accounts for the largest proportion of the processing time of femoral parts. The traditional methods of these surface treatments are scanning milling using ball-end mills. Although this meets the required surface finish of the parts, the small step spacing can result in a very long processing time. The SGS series barrel tools achieve a step distance of up to 3.0mm, a feed rate exceeding 800mm/min, and at the same time meet the surface finish requirements of the tolerance. Barrel milling cutters are a variant of taper ball-end milling cutters, using a large tangential radius instead of a straight taper (φ50mm to φ1500mm).