Hybrid Abrasive Tool that Grinds and Polishes Precision Components in Less Time

Fixed- and Loose-Abrasive Combination Achieves a Smooth Surface that is Equivalent to Conventional Magnetic Abrasive Finishing Methods

This hybrid abrasive tool comprises both fixed-abrasive and loose-abrasive phases, leading to significant reduction in production time and cost for precision components. The fixed-abrasive simplifies the abrasive insertion into slender tubes such as needles and catheter shafts. The loose-abrasive guarantees the uniform distribution of the abrasive along the workpiece surface. This hybrid abrasive tool is useful in biopsy needle finishing, a medical device market expected to grow to $2.1 billion by 2018. With more than 14 million new cancer diagnoses globally each year, the demand for biopsy devices that can improve cancer diagnosis and treatment and are minimally invasive is steadily increasing.

Research demonstrates that smoother needles can collect 55 percent more tissue without the use of larger biopsy needles. Researchers at the University of Florida have developed a hybrid abrasive tool that saves about 80 percent abrasive insertion time in needle finishing while achieving a smooth surface equivalent to available magnetic abrasive finishing methods. In addition, the hybrid abrasive tool is not limited to internal polishing. The hybrid abrasive tool can be used for free-form die-and-mold polishing. Conventional finishing requires two steps, grinding and polishing. The hybrid abrasive tool combines the two steps and minimizes errors and imperfections caused by repositioning between steps.

Application

Hybrid abrasive tool with both fixed- and loose-abrasive phases for reduction in production time and cost for precision components

Advantages

• Simplifies the abrasive insertion into slender tubes, facilitating the internal finishing of tubes more than 1 m long.
• Performs both grinding and polishing, reducing positioning errors common with chucking and un-chucking components between steps
• Saves about 80 percent abrasive insertion time, significantly reducing production time and cost

Technology

The hybrid abrasive tool works initially as a fixed abrasive but also works as a loose-abrasive once the abrasive binder dissolves into the lubricant. The fixed-abrasive configuration simplifies the abrasive insertion, and the loose-abrasive configuration guarantees a uniform abrasive distribution along the work-piece surface. The time needed to transition from the fixed-abrasive phase to the loose-abrasive phase depends on the dissolution rate of the adhesive and can be controlled. The lubricant bonds magnetic abrasive to a rod for easier insertion of the tool into slender tubes. The hybrid abrasive tool facilitates the tool insertion and improves the overall robustness of the process.