How to select the suitable shoting and blasting media for different products ?

A. Surface strengthening:

designed to enhance the fatigue life and stress corrosion resistance of components. High-speed shot impact on the surface induces plastic deformation in the material, forming a beneficial residual compressive stress layer that effectively inhibits crack initiation and propagation. Typical applications include transmission gears, suspension springs, and aircraft engine blades.

• Preferred media: steel balls and ceramic beads. These media possess high density and hardness, enabling them to transfer sufficient kinetic energy to stably achieve the specified Almen strength and coverage ratio, thereby forming a beneficial residual compressive stress layer on the workpiece surface.

B. Surface Finishing:

A process aimed at achieving an aesthetically consistent matte, satin, or soft reflective finish, commonly used for mobile phone casings, medical devices, stainless steel kitchenware, etc. The core objective is to ensure a gentle impact resistance and prevent random scratches, thereby creating a diffuse reflection texture.

• Preferred media: glass beads and ceramic beads. Spherical media can produce uniform micro-roughness, offer controllable surface roughness, and are less likely to embed into the workpiece surface. If a softer dulling effect is required, fine-grained white corundum may also be selected.

C. Surface cleaning:

This process requires rapid removal of rust, oxide scale, old coatings, or burrs, such as shot blasting for castings and forgings or pre-treatment for steel structures to achieve corrosion protection. This application demands that the cutting medium possess sharp edges and high hardness to provide strong cutting force.

• Recommended cutting media: square steel grit, alumina (corundum), and garnet. These media exhibit high hardness and strong cutting force, enabling rapid removal of stubborn contaminants while providing an appropriate anchor pattern depth that facilitates subsequent coating adhesion.

A. High-strength steel, cast iron, and other hard metals:

Steel balls, ceramic beads, and other high-strength media can be used safely to achieve enhanced cleaning or highly efficient cleaning results.

B. Stainless steel, titanium alloy, etc.:

Iron contamination must be completely eliminated. Ordinary carbon steel balls may leave iron residues, which can induce galvanic corrosion in humid or corrosive environments, leading to rusting of workpieces. Ceramic beads or glass beads should be selected instead. For titanium alloys, special attention must also be paid to the risk of hydrogen embrittlement; due to their chemical inertness, ceramic beads have become the ideal choice for strengthening aerospace titanium alloys.

C. Soft metals such as aluminum, magnesium, copper alloys, etc.:

It is recommended to use media with mild impact force, such as glass beads, ceramic beads, or resin-based plastic sand; hard media, such as steel shot, can easily embed into the surface, leading to stress concentration or potential electrochemical corrosion risks, and may also cause deformation of thin-walled components. The shot blasting intensity must be strictly controlled (typically by selecting a relatively low Almen value).

D. Non-metallic materials such as plastics and composite materials:

Low-impact, high-elasticity soft media—such as polyamide particles, walnut shell powder, or corn cob fragments—must be used to effectively remove burrs and overflow material without damaging the substrate.

A. Continuous batch production:

It is recommended to select highly durable and recyclable media, such as steel balls or ceramic balls. Although their initial procurement cost is relatively high, their extremely low wear rate can significantly reduce long-term production costs.

B. One-time or small-batch operations:

Mediums with lower initial costs, such as glass beads, may be considered; however, it should be noted that glass beads are fragile, and the dust generated upon their breakage can reduce visibility and increase the dust removal load, making them unsuitable for long-term continuous operation. If high surface quality requirements are present, although ceramic beads are more expensive, they can achieve a more consistent surface finish at a lower consumption rate.

C. Pursuit of maximum processing efficiency:

The higher the medium's density and hardness, the more concentrated the kinetic energy transfer becomes, resulting in a faster cleaning or strengthening rate. High-hardness steel shot and corundum can remove thick oxide scales within an extremely short period of time; however, it is necessary to balance this efficiency against the potential increase in surface roughness and the risk of workpiece deformation.