**Abstract**

 Modern times cannot be imagined without the use of hybrid-machining processes to achieve improvement in surface finishes. Abrasive flow machining (AFM) is one of these processes. It is a non-traditional machining technique that can be used for deburring and polishing to achieve surfaces such as complex geometries and edges by using a flow of pressurized abrasive laden viscoelastic polymer. It is very capable and appropriate for the finishing of complicated inner and outer surfaces and it has been experimentally confirmed that AFM can improve surface quality significantly. The proper combination of manufacturing circumstances is one of the most significant aspects to take into consideration in the popularity of industrialized processes. This paper highlights some of the existing methods of AFM and its effort to optimize them in order to improve the surface finish with few outlays.

**Keywords:** abrasives, AFM, surface finish, material removal rate

#### **1. Introduction**

Today's modern industry requires highly accurate and precise small-sized products. The majority of time taken and the most labor-demanding section of the process in today's manufacturing is the supreme finishing of intricate parts of a small size. Moreover, surface roughness of the final product has a significant role in various industries such as aerospace, automotive and biomedical, etc. A tiny burr or a cut will cause giant losses such as collapse of aerospace devices, energy loss in engines, breakage of components etc. In the earlier years, industries were using conventional super-finishing processes to acquire the necessary smoothness on the product. These traditional processes are not suitable for intricate geometries and complicated profiles to be machined to a higher level of finishing requirements. Advanced finishing processes have become more popular because the complicated inside geometrical features in various engineering materials can be finished with a desired accuracy. The aim of achieving nano level surface smoothness during machining is easily achieved by these advanced processes, which are demanded of today's industry.

Abrasive flow machining (AFM) was first described and patented by McCarty, the president of Extrude Hone Corporation in 1970 [1]. Because of its capability to machine interior and curved surfaces, it is considered as a suitable surface finishing process to finish internal complex geometry of work pieces. Presently AFM is well known as one of the greatest techniques for finishing of multifaceted geometries not easily reached by the traditional techniques. Investigators are always trying to achieve better results in the AFM process. The proper combination of manufacturing conditions is one of the chief aspects to improve the performance of newly developed processes and mainly in processes associated to AFM. This paper presents some of the literature available on the AFM process for process parameter optimization and to achieve a superior surface finish.
