Optimization of hot press sintering parameters for basalt fiber reinforced impregnated-diamond drill bit matrix composite materials using response surface method

To improve the bending strength of diamond drill bit matrix prepared by hot-press sintering, the bending strength of the sintered samples was used as the response variable. The effects of factors such as insulation time, pressure holding time, temperature, pressure, basalt fiber (BF) content, and diamond concentration were investigated. Significant factors affecting bending strength were screened using a Plackett-Burman design. The steepest ascent method and Box-Behnken response surface methodology were employed to optimize the hot-press sintering process, 32 sets of tire block samples were sintered. The results showed that insulation time and BF content were significant factors influencing the bending strength. After response surface optimization, the optimal hot-press sintering parameters were determined as follows: insulation time of 5 min, pressure holding time of 5 min, temperature of 960 °C, pressure of 15 MPa, diamond concentration of 20 vol%, and BF content of 0.586 %. Under these conditions, the bending strength of the samples reached 377.8 MPa, with experimental values closely matching the predicted values. The experimental results provide theoretical guidance and technical support for optimizing the hot-press sintering parameters.