Why is the Center in Tension?
Consider that each ring segment has the same volumetric expansion. Next, take the mid-wall circumference and multiply that by the volumetric expansion resulting from...
Determining Transformation Products
Transformational stresses arise from the volumetric expansion of the Face Centered Cubic (FCC) crystal structure to Body Centered Cubic/Tetragonal (BCC/BCT). The degree of volumetric...
Selecting the Best Application Combination
While large heat-treated components will always contain some stress, these stresses can be minimized in order to reduce the likelihood of catastrophic failure while...
Sorting Through the Forging Selection Process
The forging process, one of the oldest methods of metalworking, is often still the best suited for many part applications. Due to upgraded computer...
Powder Metal Gears, Part IX
In Part IV, Macro Design was discussed and a corrugated web was presented. The idea of the corrugated web came from several directions and...
Powder Metal Gears, Part VIII
Another finding demonstrated by Dr. Strehl’s manufacturing simulation was the reduced investment costs for a new gear factory when going the PM route. In...
Powder Metal Gears, Part VII
So far, five powder metal gear related topics have been covered: effects of porosity, noise and NVH, micro design and robustness, macro design and...
Powder Metal Gears, Part VI
The heat treatment issue discussed in previous columns remains for the rollforming as well; low-pressure carburization helps, due to a better process when introducing...
Powder Metal Gears, Part V
So far we covered porosity of powder metal and some of its effects: Noise and NVH, macro design and reduced weight, and micro design...
Powder Metal Gears, Part IV
In the previous article, the micro design, in the sense of profile modifications to the teeth, was discussed. This fourth article will deal with...
Powder Metal Gears, Part III
Since the Young’s modulus and Poisson’s number are density-related, it is important to use the PM relevant numbers in the design phase of the...
Powder Metal Gears, Part II
NVH is one of the most difficult areas of gearing approaching black art. Transmission developers have their own standards for testing. Often subjective measurements...
Powder Metal Gears, Part I
This will be the first in a series of smaller articles on Powder metal gear technology. Each article will focus around a topic that...
