Home Forums General Discussion Media, Shot, Beads, etc. Glass Bead Inspection and Type 2 Saturation Curves

1. How can I do the shape test for glass bead incoming inspection? I look up to AMS2431-6
3.10.7 Shape
A visual count shall be made of three fields of approximately 100 beads each, on the sample prepared as in 4.1.6 using a microscope with 20X magnification and sub-stage lighting, or an optical projector. The three results shall be averaged and compared to Table 1.

I think this method is difficult to perform, since how do I know each field contains 100 beads? Can you advise me other way to do shape incoming test. By now, every time we buy a new lot glass bead, we will do incoming test , including shape and size

2. In SAE J443,there are two type of saturation curves, however I can’t understand this type of curves,

My question is when can this saturation curves can be used ? In SAE J443, it states that this will occur only when process variables do not permit attaining earlier data points. I don't understand this means. Can you give me detail explanation about that?

Q1. Modern technology can be employed in test procedures. My own technique involves using a small spoon to feed a shot sample into a frame that has been glued to a glass slide. The amount fed in is just less than is needed to form a monolayer. An SLR digital camera is then used to take a date-stamped photograph of the sample - illuminated from below by a light box. This is repeated twice - to give the required three samples. The three digital images are then transferred to a computer program (CorelDraw in my case). The images are cropped so that approximately 100 particles are on view. Note that the specification requires APPROXIMATELY 100. The images are then examined to establish whether or not the specified percentage of 'spherical' particles are present. Estimating 100 particles is simplified by counting the number of particles that intersect the borders of the cropped image. With a 3 to 2 aspect ratio of a camera's image you only need to establish that 12 to 14 particles intersect the longer side of the image. With practice this whole procedure is very quick. I do however also use image analysis computer programs to assess both shape and size of the sample particles.
Q2. The answer to this question can be found on page 30 of a The Shot Peener article - Fall 2012 ("Satisfactory Peening Intensity Curves"). The Type II curve is only allowed for the defined "Spopecial Cases". Generally only one type of curve is allowed.

how can we measured and calculation of penning intensity?

Amit89,

I recommend getting copies of J442 (http://standards.sae.org/j442_201302/) that will show you what equipment you will need. Then you'll need a copy of J443 (http://standards.sae.org/j443_201006/) that describes how you use the items in J442 to calculate intensity.

That is just the beginning. You will likely need to review other specifications depending on what industry you serve.

I'm guessing you're new to the shot peening world so I'd also like to recommend visiting http://www.shotpeeningtraining.com/

Dear Dave

thanks for positive reply

but how can i download it from site its chargeable?

thanks
amit89

Yes, the specifications are copyrighted and subject to a per copy fee. Instructions for download are on the site.