Optimization of stress in the anvils of an opposed-movement multianvil device

In an opposed-movement multianvil high-pressure device, the anvils slide against each other, inwards or outwards, without any extrudable gasket. In this device, accurate controlled support pressures can be applied on each flank of all the anvils. A finite-element analysis of these anvils is made using a derived Mohr-Coulomb criterion; the support pressures applied over the anvil flanks are determined so as to place the anvil material in the optimum stress state. The results show that maximum pressures of 20 GPa can be obtained with specific support pressures using tungsten carbide anvils. Samples of any volume could be subjected to this pressure as there is no design-related size limit when scaling up this opposed-movement multianvil device.