| Diamond composites are widely used in various industries for their excellent properties.Common methods for industrial preparation of diamond composites include hot-pressing,cold-pressing,and non-pressure methods.Among them,the preparation of diamond composite by hot-pressing method requires less pressure than the cold-pressing method and the temperature is lower than that of no-pressure method,so it is more widely used.During the preparation of diamond composites by hot-press sintering,when the matrix composition is certain,the main factors influencing the performance of diamond composites are the process parameters in the sintering process.This article mainly studies the influence of the sintering parameters(sintering temperature,holding time,sintering pressure)on the performance of the diamond composite during the hot-press sintering process.The formula of the carcass composition selected in this article is Fe60%,Sn2%,FCu70 38%.During the test,one parameter is adjusted to ensure that the other two parameters are not changed,and the sample is loaded and hot-pressed;then,the sample obtained by sintering under the remaining parameters is obtained by the same method.The sintered samples were measured for density,hardness,and bending strength,and analyzed by metallographic analysis,XRD,and fracture SEM morphology.The influence of each parameter under this recipe on the density,hardness and flexural strength of the sample was studied in detail to determine the optimal sintering process parameters and provide recommendations for actual production.The effect of sintering temperature on the performance of diamond composites was investigated.Sintered samples were obtained after changing the sintering temperature(700 °C,740 °C,780 °C,820 °C,860 °C),and their mechanical properties were tested and analyzed.The results showed that the overall density and hardness of the sample increased with the increase of temperature,and the increase range from 700 °C to 780 °C was large,the density increased from 82.5% to 96.6%,the hardness increased from 75.4 HRB to82.3HRB,and the temperature was 780 °C.The rise at 860 °C tends to be flat,the density rises from 96.6% to 97.1%,the hardness increases from 82.3 HRB to 85.7 HRB;the bending strength of the sample increases first and then decreases with increasing temperature,when the temperature rises from 700 °C to 820 °C.At that time,the bendingstrength increased from 632 MPa to 767 MPa,the temperature increased from 820 °C to860 °C,and the bending strength decreased from 767 MPa to 760 MPa.When the sintering temperature is 780 °C,the overall performance of the sample is good.The effect of holding time on the performance of diamond composites was studied.After changing the holding time(10 s,20 s,30 s,40 s,60 s),sintered specimens were obtained and their mechanical properties were tested and analyzed.The results showed that the overall density and hardness of the sample increased with the holding time,the overall density of the sample increased from 93.9% to 97.2%,the hardness increased from81.2HRB to 84.2HRB;the bending strength of the sample with the holding time The elongation increases first and then decreases.When the holding time is extended from 10 s to 30 s,the bending strength increases from 737 MPa to 760 MPa.From 30 s to 60 s,the bending strength decreases from 760 MPa to 728 MPa.When the holding time is 20 s,the overall performance of the sample is better.The effect of sintering pressure on the performance of diamond composites was investigated.Sintered samples were obtained after changing the sintering pressure(17 kN,20 kN,23 kN,26 kN),and their mechanical properties were tested and analyzed.The results showed that the density and hardness of the sample increased with the increase of sintering pressure,the density increased from 96.0% to 97.9%,the hardness increased from81.4HRB to 85.0 HRB,and the bending strength increased first and then decreased with the increase of sintering pressure.Smaller,the pressure increases from 17 kN to 20 kN,the bending strength of the specimen increases from 707 MPa to 754 MPa,the pressure increases from 20 kN to 26 kN,and the bending strength decreases from 754 MPa to 690 MPa.When the sintering pressure is 20 kN,the overall performance of the sample is better. |
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