MEC 431 Lecture Notes - Lecture 20: Sintering, Compressive Stress, Heat Treating

• School: Ryerson University
• Department: Mechanical Engineering
• Course: MEC 431
• Professor: N/ A

Document Summary

16: compresion ratio = (eight of loose powder (eight of green compact, or. = density of green compact apparent density of loose powder. Example compression ratio: an engineer wishes to design a die to press a bronze gear. If the resulting green compact gear is to be (cid:883). (cid:884)(cid:882) dia. and (cid:882). (cid:888)(cid:884)(cid:887) high, how long must the die be? (compression ratio for bronze is 2. 3) Porosity = 1 density: where the above density is expressed as percentage of the theoretical. 450 kn (50-ton) hydraulic press for conventional pressing of pm parts (photo courtesy of dorst america, inc. ). Strength: as can be seen, density and strength increase with higher compacting, (owever, with every material, there is an maximum pressure, where little advantage is gained pressure. Design considerations: powder metallurgy lends itself to certain shapes. 24 strength and hardness (absolute scale: (eat treatment to bond the metallic particles, thereby increasing.