Before you determin to use Metal Injection Molding technology to finish you parts, you must clear know the mechanical properties they required and the parts' applicaitons.Then let the MIM manufacturers learn it clearly.After finish this job, then you could make your 2D/3D drawings with all your requirements and release them. After we get your drawings,we would carefully evaluate your drawings and learn its applicaitons to see if we could do or not,or we require you to do some adjustment on the drawings, such as the dimension tolerance,surface roughness, mechanical strength, hardness,surface treatment,dynamic load, wear resistance, machinability and corrosion resistance, etc,then we would communicate with the customers to see if they could accept or not. Before building the mold, all the information on the drawings should be confirmed by customer and us. After the customer approve,our engineer would make a mold DFM for the customer to check,,after all the details are approved by the customers,we would build the mold.
Regarding to the MIM material,various stainless steel and ferrous material could be used on MIM process,but SS304/316 could not be hardened by heat treatment, since they are austenitic stainless steel.
While the martensite stainless steel SS17-4PH,SS440C,SS420 could be hardened by quenching and tempering to get a high hardness and a good wear resistance.The ferrous material that consist 0.3% or more combined carbon can be quench hardened and tempered too. The hardness of 17-4ph could reach 40-48HRC after heat treatment,while the hardness of SS440C could reach 58-63HRC.
Generally,in order to get the best strength and wear resistance, we have to do tempering or stress elimilation after quenching process, and the tempering temperature is pretty important,if the temperature could not be controlled well, the parts would be cracked.The MIM ferrous parts that finally doesn't contain carbon or its carbon content is low can be carburizing-quenched, if so,the surface hardness could be improved and the toughness of the core could be kept well.
Sints company recommends the customers to do vacuum heat treatment processing and (or) carburization for MIM ferrous base parts,but the temperature should be controlled closely.
