Effects Of Phosphorus-containing Pre-alloyed Powder On The Microstructures And Properties Of Fe-based Matrix

Phosphorus can effectively reduce the sintering temperature,improve the mechanical properties of diamond tool's matrix,and inhibit the thermal erosion of diamond.In this paper,two kinds of phosphorus-containing prealloyed powders-CuP8and FeP24 were used as research objects.By using the test and analysis methods like SEM,EDS,XRD,hardness,bending strength to make certain how different kinds of phosphorus-containing prealloyed powders to effect the microstructure and performance of iron-based matrix.The results show that FeP24 is composed of FeP phase and Fe₂P phase,the hot-pressing ability of FeP24 is poor.CuP8 is consists of Cu and Cu₃P phase,the hot-pressing ability of CuP8 is good.CuP8 is significantly better than FeP24 in preventing diamond thermal erosion,but slightly diamond thermal erosion could improve the bond strength between diamond and matrix.Adding phosphorus-containing prealloy powder to Fe-Cu-P matrix and found:CuP8will melted,the matrix which containing CuP8 is consisted of?Cu?,?-Fe and Fe₃P phase,all the Cu₃P phase is successfuly convert to Fe₃P phase;FeP24 will not melted,due to the newly generated Fe₃P phase ring's isolate effect,the matrix which containing FeP24also keep its unconverted Fe₂P phase.This phenomenon affects the strengthening efficiency of FeP24,That's the reason why the matrix which containing CuP8 has better bending strength and hardness than the matrix which containing FeP24.The hardness and bending strength of matrix are influenced by the weakening effect of copper and the strengthening effect of phosphorus,phosphorus'strengthening efficiency of different kinds of phosphorus-containing prealloyed powders are different.When the phosphorus content reaches 0.8%,the hardness and bending strength of the matrix which containing FeP24 are close to the maximum.However,until the phosphorus content reaches 1%,the hardness and bending strength of the matrix which containing CuP8 are close to the maximum.CuP8 pre-alloyed powder has lower melting point and finer particle size than copper powder,which results in the matrix which containing CuP8 has higher density than the matrix which containing FeP24.Sintering process can effectively affect the performance of matrix.For the matrix which containing 10%of CuP8 and 90%of iron powder,setting the sintering temperature,sintering pressure,and sintering time as 820?,30kN and 270s respectively will help matrix obtain a satisfactory mechanical performance.