Great explanation! I like your series of informative videos. For this topic, I would refer to a publication from Mahle, who have clearly shown the advantage of forged vs. sintered conrods concerning fatigue life. Keep up the good work! Hans-Willi Raedt, VP Advanced Engineering, Hirschvogel Automotive Group
I have some videos on my Industry playlist you might like. I'd heard the term "Cracked Powdered Metal Connecting Rods". WHAT?. The cracking off the cap eliminates the milling the big ends round after cutting off the rod cap. PM saves on that expensive/time step.
What pisses me off about powdered metal is (other than when connecting rods fail at as little as 7k miles.. those things are ticking time bombs with random lifespans) that they pass them off as an alloy when it's not an alloy. An alloy like bronze is an entirely new metal where two or more metals (in bronze it's copper and tin) form a bond on a molecular level and everything about the metal changes. In these PM 'alloys' you can clearly see that the extra types of metal are just flakes in a sea of black (or whatever color it is) it's not actually bonding into the host metal and is actually not adding a benefit, if anything it just is a weak point. It's only when those metals being alloyed together are heated to their melting point that they will fuse and become and actual alloy.. I trust cast iron connecting rods far more than powdered metal ones.. And why am I so focused on connecting rods? They are the single most highly used PM part in the world, nearly every auto manufacturer has gone over to them since 2003. Even Ford trucks which have always had forged cranks and rods in their engines even when all the car engines Ford made had cast, now have PM connecting rods.
Diffusion alloying is a thing. During sintering, alloying elements fully diffuse into the microstructure of the base iron without any melting occuring (unless there is some transient liquid phase sintering occuring as is the case when copper is used as an alloying element).
Great explanation! I like your series of informative videos.
For this topic, I would refer to a publication from Mahle, who have clearly shown the advantage of forged vs. sintered conrods concerning fatigue life.
Keep up the good work!
Hans-Willi Raedt, VP Advanced Engineering, Hirschvogel Automotive Group
Porsche uses powder forged rods in there 928 cars,and others, so does newer Corvette
I have some videos on my Industry playlist you might like. I'd heard the term "Cracked Powdered Metal Connecting Rods". WHAT?. The cracking off the cap eliminates the milling the big ends round after cutting off the rod cap. PM saves on that expensive/time step.
What pisses me off about powdered metal is (other than when connecting rods fail at as little as 7k miles.. those things are ticking time bombs with random lifespans) that they pass them off as an alloy when it's not an alloy. An alloy like bronze is an entirely new metal where two or more metals (in bronze it's copper and tin) form a bond on a molecular level and everything about the metal changes. In these PM 'alloys' you can clearly see that the extra types of metal are just flakes in a sea of black (or whatever color it is) it's not actually bonding into the host metal and is actually not adding a benefit, if anything it just is a weak point. It's only when those metals being alloyed together are heated to their melting point that they will fuse and become and actual alloy..
I trust cast iron connecting rods far more than powdered metal ones.. And why am I so focused on connecting rods? They are the single most highly used PM part in the world, nearly every auto manufacturer has gone over to them since 2003. Even Ford trucks which have always had forged cranks and rods in their engines even when all the car engines Ford made had cast, now have PM connecting rods.
Diffusion alloying is a thing. During sintering, alloying elements fully diffuse into the microstructure of the base iron without any melting occuring (unless there is some transient liquid phase sintering occuring as is the case when copper is used as an alloying element).
The Toyota Corolla 2003-2008 1ZZ-FE engine has powder forged rods and some engines surpass 300k miles.