英语翻译After pressing ,many of zhe powder particles touch one a

英语翻译
After pressing ,many of zhe powder particles touch one another .during the initial sintering stage ,neck form along the contact regions between adjacent particles ,in addition,a grain boundary forms within each neck ,and every interstice between particles becoms a pore.As sintering progresses,the pores become smaller and more spherical in shape.The driving force for sintering is the reduction in total particle surface area;surface energies are larger in magnitude than grain boundary energies.Sintering is carried out below the melting temperature so that a liquid phase is normally not present.Mass transport necessary to effect the changes is accomplished by atomic diffusion from the bulk particles to the neck regions.