Study On The Properties Of Aluminum-based Binder And Diamond Tools

With the development of social production technology,the metal bond diamond tools have been widely used in stone,glass and machining processing areas.Due to the high relative density,strength and plasticity of metal bond,the self-sharpness of diamond tools are poor resulting in low machining efficiency.To solve the aforementioned problems,the mixed powder of Al-Cu-Mg-Ti-Cr was used as binding agent,and metal bond diamond tools with good self-sharpness were fabricated using hot pressed sintering method.The effects of the sintering temperature,Cu content and Ti content on the properties of the Al-based binding agent and diamond tool were studied.The main research results were as follows:1.With the increase of sintering temperature,the relative density,bending strength and hardness first increased reaching the maximum of 98.84%.334Mpa.97HRB,respectively at 560?,and then decreased.In all the temperature,the A1 was the main crystallization phase,and the diffraction peaks of Al2CuMg,Al3Ti and Al2Cr alloy phases increased with the increasing temperature.When the sintering temperature was lower than 560?,the crystal grain was uniformly distributed,and the fracture model was dominated by transgranular fracture.When the sintering temperature was 600?,the growth of crystal grain leaded to the intergranular fracture.2.Results show that when the sintering temperature was between 560? and 600?,chemical reaction did not happen between Al-based binding agent and diamond surface,indicating that the holding force of bond to diamond is mechanical package.When the sintering temperature was 560?,the relative density of sintered metal bond bodies was larger,and the content of metal wrapped on diamond surface was higher.At this time,the diamond can be completely covered with metal bond.3.The effects of Cu content on the mechanical properties of the sintered bond bodies,the interface of bond and diamond and the product at the interface were studied.With the increase of Cu content,the relative density,hardness of Al-based binding agent,the strengthening phase of Al2CuMg and the dispersion phases of Al3Ti and Al2Cr increased gradually,while the bending strength increased first and then decreased.When the mass ratio of Cu was 4.5wt%and the sintering temperature was 560?,the comprehensive mechanical properties of binding agent were optimal,and the fracture model was dominated by transgranular fracture.At this time,diamond could be well wrapped by the binding agent.The loss ratio of diamond tool specimen reached the lowest point of 12.8%,the strength loss rate is reduced 3.5%,and the grinding ratio was improved by 9.7%.and the surface roughness of workpiece reduced from 0.115?m to 0.092?m.4.With the increase of Ti content,the relative density,hardness of Al-based binding agent,the content of Al3Ti dispersion phase increased gradually,while the bending strength increased first and then decreased.When the mass ratio of Ti was 4wt%and the sintering temperature was 560?,the diamond could be well wrapped by the binding agent.Compared to the diamond tool specimen without Ti,the strength loss rate is reduced 3.1%and the grinding ratio was improved by 8.6%.And the surface roughness of workpiece reduced from 0.125?m to 0.085?m.